People are still requesting this document from an earlier comment to a post even a year later so I decided to post the whole thing. This was an article in one of the communities when I started at WGU in 2013. Hope it helps you as much as it helped me.
15 Secrets of Accelerated Success (helped me get my MBA in 6 months) I wish someone would have explained the following to me in detail when I started. If I had this information then, I would be further along than I am right now. Today, I had some extra time and thought I would write it all down for someone else to use. I know it is long, but I promise that something in this will help you. I originally posted this only in the MBA community, but had several requests to repost it here. Several people working on their BA/BS have emailed me to get this stuff, and I thought it would be easier if it was posted. I started the MBA PROGRAM on March 1, 2012. I completed all the assessments on August 16, 2012. 5 months and 16 days to complete the MBA program. Here are the things I have learned and the things that helped me:

1. Because everything is online, you have to start thinking online. Everything in the program is electronic; the books, the program, the mentors, the course teachers, everything. You have to stop thinking like a traditional student and start functioning as an online student. You work on one class at a time, drowning yourself in information and submersing yourself in the “stuff” of that area. This is different than having 3-4 classes a semester. FOCUS on the class you are in and nothing else. As an electronic student you must also adapt and use technology to better use your time and energy. Using as many electronic tools as possible will help you get done faster.
2. Get a second, side-by-side monitor for your computer. If you are trying to do this online with one monitor, you are losing valuable time, cannot organize info properly, and it will be harder than it needs to be. On my left monitor I have MS OneNote, on the right hand monitor I have the COS, e-texts, the communities and almost everything else. When I read the e-texts and course information, I take a screen clip of what is important and insert it in OneNote in an almost fluid movement that takes about a second and I keep reading. (More on OneNote later) Then when I am ready to write, I have all the important notes and info on the left screen as I write on the right. I never have to go back and open the text to find the info I need it is always on the other screen. Working with two monitors has saved me hours (and hours and hours). The cost for an additional monitor is silly ($70-100 for a 20”). I have two 20” screens and that is all you need. If your computer does not have two video ports, you can use an external video adapter (Google “external video adaptor”) get a USB 2.0 they run $39-$120.
   
3. Get OneNote from Microsoft. You should not care if it costs you a little money (invest in yourself!). Go back to number one in this list. OneNote is a program that is underutilized and not well known. It is an organization program that allows you to organize your classes as tabs along the top and the readings and activities in pages along the right side. I have all my classes in tabs (Financial analysis had three tabs, Strategic management has two) then I add a page (right hand side) for each new section, chapter, Skills soft module, etc. As I read, I add notes and information to the page. HERE IS THE SECRET: in the menu there is a “clip” button that will allow you to take a picture of anything on your screen and insert it to the page in OneNote where the cursor is. Instead of typing notes, I click on the “clip” button, highlight the section of text, the figure, the picture or whatever (yes even during the skillsoft modules) and unclick. It is inserted to that page. That is why I never have to go back to the text to “find” something. I have it all right there. Is it legal? YES! You are making a copy just like if you were to make a copy from a text book for your own use. I even take pictures during the webinars as they give you tips and info about the tasks. I use the 2007 version. It costs $38.99 on amazon.com. It will be the best $40 you spend, ever! (Only slightly more important than the second monitor). You can also buy OFFICE 10 at the WGU bookstore for $99 and it has OneNote in it.
   
4. You will be told everywhere to read the task and the rubric before you start the class. I will take it a step further. Every single prompt (question part, in the MBA program they are the A, A1, A1a, B1, B2 things) within the task has key words (sometimes they are in the webinars too). Take the task, print it and get a highlighter. Highlight every single key word or phrase in each prompt in the task. Once complete, have it handy every time you read anything in the COS. Now the next part is critical, READ THE KEY PHRASES OR WORDS EVERY TIME BEFORE YOU START ANY CHAPTER OR MODULE. Read the task anytime you start anything. Then as you read you will see those same key phrases and words so you know what to pay attention to. How do you know what is important if it is not at the front of your mind? When you read the key words every time before you start reading chapters, you will get accustomed to having the light go on when something is important. You will start to read faster and you will remember more. As you read, add the name of the book, and the page number (or place you put it in OneNote) next to the key phrase. Then when you write, you have easy access to the information.
   
5. Do NOT wait until you are done with all the reading to start the task. DO THE TASKS WHILE YOU DO THE READINGS when possible. I learned this during the Financial Analysis course. Instead of waiting until the chapter was done to figure stuff out; I opened the spreadsheet on one monitor as I read on the other. Then as I learned what something was, I could look at it, or try it out with the data from the tasks. Then I started writing as I read the information. Every class since I have written as I read, and WOW, the last four courses I got almost strait 4’s on all my assessment prompts! What’s better is that my retention is great! I look through my OneNote and everything comes back fast.
   
6. SECRET WEAPON #1: Take a look at the COS. It is broken up into classes, then it is broken up into competencies, then each competency is broken into sections, and each section is broken up into activities. For your info, there are 31 assessments for all the classes. Remember number 1 of this list? Stop thinking about them as classes or assessments and start thinking about them a 1 hour blocks. When you do, you will start to be able to work through little pieces in hours and stop trying to figure out years or months. If my activities are broken into hours I can do something special with my time… I can manage it. When I plan my day, I think, I have four hours to work on something today…. Well, look here, I have two 60 minute activities and four 30 minute actives… I will get them all done. Then I get the reward for checking them off my list and feel great for using my time wisely instead of … UHG! I have so much left to do in this class!
   
7. SECRET WEAPON #2 that makes SECRET WEAPON #1 work. You need a system to make #6 possible. You need somehow to keep track of your little pieces. I use a program called leankitkanban (yes the same Kanban as in supply chain management). It is free and it is online, just like your program. www.leankitkanban.com . What I do is before each course I take 30 minutes and create a card for each activity in the segments of the COS. You will learn as you do them to recognize activities that take 30 minutes (like watching a webinar), which ones take 60 minutes (chapter in a book) and which ones take more. For chapters I usually give 60 minutes, some skillsofts are 30 some are 90 minutes. Tasks range from 240 to 600 minutes. I use the colors (type) of the cards to signify if the task is an assessment a reading, or an “extra.” (extras are for other to do items) I have five columns that the cards can move through. The first is the course and to do items. In this column I have every single activity that needs to be done for the course, including things like watch the webinar, read the rubric and read the task. I use the size box to give it the minutes we discussed earlier. I also use the due date for things that have due dates (Leadership and Strategic Management courses). The second column is what I am doing next. I move cards out of the first column into this one the day before I plan to do them. This gives me an idea of what is next. The third column is DOING TODAY. I move the cards into this column at the first of the time period that I have to work. This provides me with motivation to get them done, and a sense of accomplishment when I do get them done. The fourth column is Completed and contains the cards I have completed. This does two things. First it shows me what I am getting done in the time allotted and to see if it needs to be adjusted. Second, it gives me a sense of accomplishment. I don’t move cards out of this column until I start the next day to remind myself how well I did the day before. The last column is pending and is used to track tasks in Taskstream. Until I pass, it remains in the pending column. I know it sounds like a lot, but it is so great to move things through the system. I don’t worry what is still left to be done; I worry about what I am doing next. THEN IT ALL GETS DONE!
   
8. I never want a time where I don’t have something in task stream. I do not wait to get things back before continuing on. It is useless to wait around 4-5 days before going on. In all my classes so far I have a grand total of 6 rewrite prompts on three tasks out of 126 prompts (I think) so far. (5% ) Besides, the majority of the time, the next thing I read or write seems to help me with the rewrite (even if it is in the next course).
   
9. I was also told that you should just plow ahead and do the tasks even if you don’t really understand and that by having to do rewrites you will learn what you need. I THINK THIS IS STUPID. I have always lived by “*doing it right the first time take less time than having to do it again.*” I read everything in the COS, and I study it. I do rough draft sections of the tasks and go on, but will always come back and rewrite it before I send it in. Here is a piece of advice… The task are not homework, they are tests. They show that you grasp the information and can write about it.
   
10. I was amazed when I was doing the Leadership course that my team members did not know how to use the citation tools in MS WORD. What?! You don’t know about the citation tools in MS WORD? It does all the work for you. I have never gotten a single reference wrong, or even had to think about what I was doing to cite a work. GET TRAINED IN USING IT. You have an Atomic Learning license from WGU. Search “atomic Learning” in the communities to learn what the password is and website is. Go there; go to WORD training, for type just put software. Then go to citations and bibliography and watch all the videos. (Takes about 8 minutes). Then you can use the tools and never have to worry about it again.
    
11. Use the course mentors. Call them, email them and get info from them when you have questions. I learned this important lesson in Financial Analysis. I had a question, and figured I would just work on my own. I found something on the internet and it sounded like what I supposed to do. I spent 10 hours on that prompt (I am not kidding) I thought I was brilliant. It got sent back. I couldn’t figure out what the deal was so I called the mentor. He explained something to me and I had the paragraph I needed written in 10 minutes (none of the previous work was even needed!) Call them!
    
12. Finally, do the work. Every time I tried to skip something, it messed me up. Read the chapters, read the modules. Listen to Skillsoft and do everything in the COS.
    
13. I am a writer. I have two novels that have been published (The Endowment & Sun the Starfarer, written with my daughter). This doesn’t mean I have perfect grammar. In fact, my grammar is awful. AWFUL! What I found was www.grammarly.com. Buy the WORD version, $95 annually, and it checks your work for grammar errors, spelling errors, plagiarism, helps with different word choices, and explains the different problems in your writing. Each time I am done with a task, I push the button to check it, five minutes later I go through all the issues (usually 75-100 per 15 pages). It takes 30 minutes or so, but when I am done, my writing is a thousand times better!
    
14. Don’t get tied up in what others write in the discussion boards. Just because they have a hard time in a class or on a task does not mean you will. I do occasionally look at what someone says about a task our when they are asking for help, but I don’t actually read what they say. What I am looking for is what course mentor say, where to find the answers, and what resources they suggest. I don’t get caught up in the person’s issues, just the solutions that were found.
    
15. Use the internet. Often, I find that there are good sources of information that are more concise than the textbooks. I stick to organizations and trade sites. For example, I had a question about supply chain management. I found much more than enough information from the supply chain management review website to answer my question. WARNING: not all information on the web is good, or from a good source. Stick to sites that are for professionals in that area. If you read this, please post a remark. It is nice to know when people are using this info. It also keeps the post near the top so it can help others.
    

~John A. Muhlestein

Putting reference in Scientific Manuscript or other document created in MS Word is a night mare. Sorry, Let me correct it, “Putting reference in Scientific Manuscript or other document created in MS Word is a night mare to only those who are ignorant” But it you are those who have similar night mare, then you have come at the right place.
📷Process of inserting references starts with importing fields like title, author, journal/site and many other things. Then comes referring at appropriate place in Word document. Most of the times, before making final document we have to change/modify/delete text and associated reference. In such case, managing reference numbering etc becomes even more cumbersome, time consuming and boring task. And finally coming to making list of reference or bibliography. If all the process are done manually in Ms Word then becomes nightmare.

📷It is seen that average researcher spend up to 2 to 3 days of time putting, updating and modifying references in typical journal paper. This time could be greatly reduced to around 30-45 min if done by using smartly. For thesis or dissertation this time generally adds up to 5-6 days also.

Ms Word has some in-build feature to import, manage and make bibliography which makes some of the task in entire process of inserting references easy. But this is just the half way. There is lot of external reference manager like Refworks, Endnore, Citavi, Zotero etc. available making the overall process of importing, searching in reference, referring and making bibliography easy. Some of the are free while other are paid. Features and ease offer by these software also vary.
So which one to use and which one offer the best features and are most user friendly among the free reference manager?
After making lot of research and comparing various reference managers I finally narrowed down to Mendeley and have been using since then and never changed looked at any other reference manager.

Mendeley

Mendeley is a free and one of the referencing manager and social network that helps you organize research, collaborate online and discover new research. One can sign up for a Mendeley account online and install the Mendeley Desktop Tool in your computer. They also have mendeley to import content from web directly (like http://www.sciencedirect.com etc), by using a web plugin. You can import papers into Mendeley library from your hard drive by simply dragging and dropping files. You can also import reference list from other reference managers or by searching various web databases for papers through Mendeley Literature Search. Mendeley desktop will display a PDF icon next to the paper if the full text is available. You can search annotate and add notes to PDF documents. You can sync your libraries to the cloud to access them anywhere. Mendeley Writing Addins are available for MS Word and LibreOffice which enables you to insert references into your article and generate a bibliography list..
If you love reading you can please go ahead and for those who like to see all the features of Mendeley software in actual practice can click on this (->) link Features of best free reference manager | reference software for importing reference &tracking references and citation tool & auto generate reference in Word -2018
Mendeley desktop reference generator can generate apa citation, mla citation etc with ease of just 1 click. Reference for research paper, thesis, dissertation, or scientific document can be generated using Mendeley. It is best tool to auto generate referencing for tracking references for scientific manuscript Reference generator or bibliography maker. Citation generator or bibliography generator can make apa bibliography, mla bibliography and in many other format. It is better than citation machine, jabref, zotero, endnote, refworks or other reference manager or citation tool or citation manager software.

Mendeley software is must for researcher before writing thesis, dissertation or research paper.

If you are wondering how to refer or how to cite references efficiently than just watch this video on best referencing software, reference manager, citation tool, bibliography generator and reference importer from website and offline local document.
Referring document or article or journal, tracking changes in references and creating bibliography at the end in MS Word used to be quite tedious and cumbersome. However now it is quite easy and can be done quickly with few clicks in your journal papereport/thesis. No need to type Paper title, Author name, journal name, date etc for document which you want to refer.
Mendeley is the best software or tool that you can use to import paper through web/file, and gets integrated with MS Word quite easily and that too free of cost,
For other important method for writing thesis dissertation , research paper are
Most people will say that you need to learn LaTeX to make good thesis however I completely disagree with that statement. Now a days MS Word has almost all the features and infact more than what LaTeX provides. Moreover you need to learn LaTeX which is time consuming task if you are new to it.
These method/ shortcut will definitely help you to write Thesis in most efficient way and in least time. My friend didn’t listen to me and had to pay price in terms of time and effort required for regular editing which could have been done automatically in word like changing figures no/referred figure, bibliography, typing equation, making table of content and all others things that could be automated. This video technique will help you not only now but in your future carrier and I bet you will save lot of time (days) by doing things intelligently.
Ms Word don’t have official LaTeX suport, but you can do almost 99% of what LaTeX can do and much more that LaTeX cannot do. If you dont believe then please see content below
1.) LaTeX has heading (h1, h2, ….) this you can do in word and they too have heading and can be customized. For more details please click on this link -> LaTeX like heading in Ms Word: Autoformat text in just 1 click using styles feature of Ms Word 2007/2010/2013/2016/2017.
2.) Numbering figures, table and equations with automatic numbering and further auto updation like LaTeX. For more details please click on this link -> Automatic numbering of Figure | Table | Equation with auto update feature on adding/deleting new Figure | Table | Equation with just 1 click
3.) Typing Equation in MS Word: For more details please click on this link -> (Complete guide in shortcut for writing|typing equation in Ms Word. and Writing equation in Ms Word like LaTeX | A short introduction)
a) Greek symbols: Shortcut for typing greek symbols in like LaTeX in Ms Word (Complete Guide)
b) Subscript and super script: For more details please click on this link -> Shortcut for typing subscript and superscript in Equation similar to LaTeX in Ms Word (Complete Guide)
c) Accents in word: For more details please click on this link -> Shortcut for typing accents like bar, vector, hat etc in Equation – Ms Word (Complete Guide)
Overall report/paper writing similar to LaTeX (in terms of easy, fast and simple) see Automated formatting in Ms Word document for Journals, Papers, Magazine etc
Most general purpose useful shortcut of Ms Word that every one should know to automate most of the task

Writing chemical equation in Word is too boring and time consuming job. However MS Word now have a shortcut way to insert chemical equation or type chemical equation and is similar to LaTeX (which is considered as best software for typing equation / chemical reaction). There we have covered short introduction simple thing like writing subscript to complicated things like how to insert equilibrium reaction arrow, reversible reaction arrow, type text above arrow, type text below arrow or type other reaction arrows and symbols.
However for sake of completeness, I have mentioned all the 3 ways to type chemical equation in Ms Word. It is up to to decide which one suits you best.
There are 3 ways to type chemical equation or chemical reaction in Word 2016.

• GUI: This method is good only if you have few chemical equation. As it requires constant movement of hand from keyboard and mouse. Even for typing simple thing like H_2 , we have to go to insert tab and then symbols or script tab.
• Ink Equation: This is good if you have touch enables screen (Tablet, Stylus or touch screen) and you enjoy scribbling/drawing. This method converts hand written drawn equation in scribbling pad into equation. However, if you are using mouse then you will have to correct lot. Hence not recommended for typing equitation with mouse. Also with stylus it will be difficult and not the fastest, if you enjoy you can use it.
• Math Auto Correct: This method is recommended. Word has a very good feature of Math Auto correct for typing equation/chemical reaction in MS Word. There is shortcut for typing subscript/superscript, arrows, write above arrows, write below arrows. For e.g. to type H_2 just type H_2 and space. There are more such shortcut. For complete detail see Smartest, fastest and easiest way to type chemical equation in MS Word (2007 and above) -Updated in Sep-2018

————————Link for other important video for writing thesis dissertation , research paper are ———————- Most people will say that you need to learn LaTeX to make good thesis however I completely disagree with that statement. Now a days MS Word has almost all the features and infact more than what LaTeX provides. Moreover you need to learn LaTeX which is time consuming task if you are new to it.
These video will definitely help you to write Thesis in most efficient way and in least time. My friend didn’t listen to me and had to pay price in terms of time and effort required for regular editing which could have been done automatically in word like changing figures no/referred figure, bibliography, typing equation, making table of content and all others things that could be automated. This video technique will help you not only now but in your future carrier and I bet you will save lot of time (days) by doing things intelligently.
They don’t have official LaTeX suport, but you can do almost 99% of what LaTeX can do and much more that LaTeX cannot do

1. Once click formatting of any text in Word using Headings/styles.
2. Automatic numbering of Figures/Tables/Equation (all types of captions) in MS Word. They also update automatically in you add or delete figures \tables\equation in between
3. Complete guide on smartest and fastest way to type equation in MS Word
4. Short guide on how to type equation in MS Word
5. Shortcut for typing Accents in word
6. Smartest way and shortcut for typing Subscript and super script like LaTeX in MS Word
7. Smartest way to type Greek symbols or Shortcut for typing Greek symbols in word like LaTeX
8. Complete tutorial or work flow for formatting scientific manuscript | Thesis | Dissertation | Word document
9. Top 5 shortcut of MS Word that every one should know .

This shortcut will definitely be useful in various stages of research paper , thesis, dissertation writing

NOTE for readers of Ramelli's A Larger Hope?
I originally wrote these posts back in 2015. In the time since then, I've made extensive edits to the originals — which at a certain point basically turned them into a series of messy notes. Later parts in the series are still a bit more structured, though.
As it pertains to the point for which Ramelli cited me as a dissenter: just to be clear, I don't think that later interpreters (like Clement) didn't perceive a distinction between the two words; only that in practice, in most Greek usage, there wasn't much of a distinction. This is amply demonstrated in Part 6 and Part 8. (There was never any Part 7.)
Here you can find separate links to all 7 parts of this series.
Here's a condensed summary.
Sandbox: bibliography, comments, and links to add/organize
John 4:14 || 6:27??
John 8:35, eis ton
Rev 14:6, Aune vol 2, pdf 230
Sir 18:1 ὁ ζῶν εἰς τὸν αἰῶνα
"Going Through Hell; ΤΑΡΤΑΡΟΣ in Greco-Roman Culture, Second Temple"
Add, Dutch eeuw, age; eeuwig, eternal; eeuwigheid eternity.
"eternal life in [future?]"; Mark 10:30, parallels? https://www.reddit.com/UnusedSubforMe/comments/7c38gi/notes_post_4/dxbqlsb/
Aristides, and Allison: "interchange between . . . are practically synonymous": https://www.reddit.com/UnusedSubforMe/comments/bgclpj/notes7/f1lsm2f/
Eternal punishment, 2TJ: https://www.reddit.com/UnusedSubforMe/comments/bgclpj/notes7/f3qmbem/
R. Grant, "Eternal fire and the occasion of Justin's Apology"
Heikki Räisänen:

Yet the repeated mention that the fire is never quenched, along with the reference to the undying worm, makes it rather more likely that everlasting torture is .

"The Use of αἰώνιος in the Concept"
Isaiah 57:16; 1 Corinthians 8:13, "never"; Mark 11:20: https://www.reddit.com/UnusedSubforMe/comments/bgclpj/notes7/f27fic7/
Saeculum: https://tinyurl.com/yyqts7n7
Eusebius, εἰς τὸ ἀεὶ (cf. Ramelli, TFE, 177, toward end)
"Ever." OE ǣfre?

Compare Old English...

Gehenna: development, and in the earliest rabbinic texts (and in NT): https://www.reddit.com/Theologia/comments/3pk2mg/test/d0y4394
Nehemiah 11:30, גיא הנם
גהנום‎ → γέεννα, like מִרְיָם → Μαρία (cf. Μαριάμ)? Peshitta Matthew 23:33,ܕܼܿܝܢܵܐ ܕܿܓܼܼܗܲܢܵܐ ‏? (Single word in rabbinic?) S1:

Silent 'alef/he in final position may interchange with mem/nun, thus closing the last open syllable ... Thus [] ... variants of [], Kidron. This phenomenon occurs in various Hebrew and Aramaic dialects. E.g., בְּבִקְעַת מְגִדֹּֽו vs. בְּבִקְעַת מְגִדֹּֽון, "in (the) Valley of Megido" (2 Chron. 35:22 and Zech. 12:11, respectively)...

Achaemenid, LXX Dan. 6.6, Δαρεῖε βασιλεῦ εἰς τοὺς αἰῶνας ζῆθι
"That age," vs. Philo on Exodus 3:15
Patristic texts on eternal punishment, Gehenna, etc.: https://tinyurl.com/yadrp8u6
Weeping and gnashing of teeth? https://tinyurl.com/ya8ypptl
"no end": Luke 1:33 (Dan. 2:44 or 7:14), 2 Peter 1:11 and Daniel 7:27; see also Luke 20:35
Hebrews 7:16-17 and ἀκατάλυτος (4 Macc. 10:11)
Hell, read the source verse(s) that Luke 1:33 draws on (Daniel 2:44 or 7:14).
(not negative?) εἰς τὸν αἰῶνα in John 14:16, and Matthew 28:20?
Aionios: almost never meant to describe how long something did last (after the fact), but how long something is intended to last before the fact, or during?
αἰωνιότης and modern Greek αιωνιότητα
https://forum.evangelicaluniversalist.com/t/scholarly-eus-assemble/12856/30
Targum, Isa 65 and 66:24, worm: https://www.reddit.com/UnusedSubforMe/comments/7c38gi/notes_post_4/dvn5p3d/
Aionios in papyri, imperial, gymnasiarch, etc. https://www.reddit.com/UnusedSubforMe/comments/7c38gi/notes_post_4/dxgrasu/
S1:

we can compare John 11.26’s πᾶς ὁ ζῶν καὶ πιστεύων εἰς ἐμὲ οὐ μὴ ἀποθάνῃ εἰς τὸν αἰῶνα, “everyone who lives and believes in me will never die.”

John 4:13-14, "again" vs. "never again"
Also Mark 11:14
Matthew 5 (also 18:9)? "Gehenna of fire," compare "fires of Gehinnom"? 2 Bar. 85:13, "the way of fire, and the path which brings to Gehenna." Also "lake of fire"?
K_l:Gehenna, 7th century, in Isidore of Seville's Etymologies?

Gehenna is a place of fire and sulphur that is believed to have been named from a valley, consecrated to idols, that is next to the city wall of Jerusalem, and which was once filled with the corpses of the dead – for there...

Josephus? War 5.12.3, "they had them cast down from the walls into the valleys beneath."
Legio X
Kimchi

Gehenna is a repugnant place, into which filth and cadavers are thrown, and in which fires perpetually burn in order to consume the filth and bones; on which account, by analogy, the judgement of the wicked is called Gehenna

K_l:

At least in the gospel of John, the consumption of Christ is connected with eternal life (6:51). We find this theme again at the beginning of the 2nd century in Ignatius, where the Eucharist is "a medicine that brings immortality, an antidote that allows us not to die but to live at all times in Jesus Christ" (which itself echoes John 3:16, ...μὴ ἀπόληται ἀλλ' ἔχῃ ζωὴν αἰώνιον).

Ignatius, Eph. 20:

ἀντίδοτος τοῦ μὴ ἀποθανεῖν, ἀλλὰ ζῆν ἐν Ἰησοῦ Χριστῷ διὰ παντός

Analogy, aei as "continual"? Quadratus:

τοῦ δὲ σωτῆρος ἡμῶν τὰ ἔργα ἀεὶ παρῆν, ἀληθῆ γὰρ ἦν, οἱ θεραπευθέντες, οἱ ἀναστάντες ἐκ νεκρῶν, οἳ οὐκ ὤφθησαν μόνον θεραπευόμενοι καὶ ἀνιστάμενοι ἀλλὰ καὶ ἀεὶ παρόντες, οὐδὲ ἐπιδημοῦντος μόνον τοῦ σωτῆρος, ἀλλὰ καὶ ἀπαλλαγέντος ἦσαν ἐπὶ χρόνον ἰκανόν...
“But the works of our savior were always present, for they were true. Those who were healed and and not just while the savior was here, but even raised from the dead were not only seen when healed and raised, but they were always present— when he had gone they remained for a long time, so that...

Also חֶ֫לֶד as analogy to aion, lifetime, etc.
See now Resurrection, Hell and the Afterlife: Body and Soul in Antiquity, Judaism and Early Christianity (Finney 2016)

• Papaioannou, The Geography of Hell in the Teaching of Jesus: Gehena, Hades, the Abyss, the Outer Darkness Where There Is Weeping and Gnashing of Teeth
  
• Rethinking Hell: Readings in Evangelical Conditionalism (esp. Papaioannou, "The Development of Gehenna Between the Old and New Testaments," etc.)
  
• Henning, Educating Early Christians through the Rhetoric of Hell (2014)
  
• Heaven, Hell, and the Afterlife: Eternity in Judaism, Christianity, and Islam
  
• Heaven and Hell: Visions of the Afterlife in the Western Poetic Tradition
  
• After Lives: A Guide to Heaven, Hell, and Purgatory
  

"Eternal" punishment in 2T Judaism: https://tinyurl.com/y3c4pcgt
Jubilees 36.10, etc.?
"The Targumists as Eschatologists"
Hill, "Hades of Hippolytus or Tartarus of Tertullian?," esp. 116f.
Henning:

While scholars have typically tried to distinguish between “Hades” and “Gehenna” in the NT, there is no evidence that the NT authors or readers would have appreciated this distinction. Duane F. Watson, “Gehenna,” ABD 2:927, has argued ...
For good summaries of the use of these terms in the first century, see Davies and Allison, Matthew 8-18, 268-69, 632-34; Outi Lehtipuu, The Afterlife Imagery in Luke’s Story of the Rich Man and Lazarus (NovTSup; Leiden: Brill, 2007), 271-5

End sandbox
Original Intro
Quite a while ago, I posted a "part five" of a series on Christian universalism, with that particular installment focusing on the use of the adjective αἰώνιος (aiōnios) in the New Testament. The interpretation of this adjective has become a particularly contentious issue in current discussion of early Christian eschatology, as it's interpretation is one of the main determining factors for whether the early Christians believed that afterlife punishment would be truly unending (or otherwise permanent), or whether there was hope for an end to this punishment and/or reconciliation.
(For introductory background on this debate for those who are unfamiliar, look up the terms "purgatorial universalism," "annihilationism," and "eternal conscious torment," which are the most commonly used rubrics for the different positions here.)
Since my original post, however, I've made some significant changes; but most important of all, I've now read the most extensive modern academic treatment on aiōnios that there is: Ilaria Ramelli and David Konstan's Terms for Eternity: Aiônios and Aïdios in Classical and Christian Texts, published by Gorgias Press.
At the continued reminding of DadIamStrong (thanks!), I'm posting a revision of my original post, followed by an extremely comprehensive analysis of Ramelli and Konstan's monograph... which will certainly take multiple posts.
Various Christian universalists have argued that the Greek adjective αἰώνιος (hereafter transliterated as aiōnios), as it's used in the Septuagint, New Testament and elsewhere, doesn't necessarily mean “eternal” as it's been traditionally understood, but can instead have several other quite different denotations. (They apply the same reasoning to Hebrew עוֹלָם, ʻolam, which is often claimed as the counterpart of αἰώνιος, though really it’s the counterpart of the root noun αἰών, aiōn. On the etymology of aiōn itself and its derivatives, see this.)
The context in which this argument is normally made is in objection to a particular eschatological doctrine called Eternal Conscious Torment (ECT). The proponents of ECT in fact largely derive their support of this from various NT verses in which aiōnios is used—which ECTists use to claim that there will literally be no end to torment in “Hell” for unbelievers/the unrighteous.
I've stated various objections to universalists' “revision” of the meaning of aiōnios before. Of course, for me, these objections come from a secular viewpoint, and have been purely philological/historical in nature (though they also don't necessarily suggest that these verses ambiguously point toward Eternal Conscious Torment, either).
In this current post, although I'll also take aim at arguments along the lines that aiōnios suggested something like "lasting for a long time but not forever," one of the major arguments I'll be criticizing is found in Ramelli and Konstan's in their Terms for Eternity, which claims -- on the basis of the derivation of aiōnios from aiōn, suggested to mean "age" -- that in early Judaism and Christianity, aiōnios mainly denoted "pertaining to the age," with "age" here understood specifically as the eschatological age: the "age (or world) to come," so well-known from the New Testament and early rabbinic literature.
Before I begin properly, let me say that I think that some of the main revisionist arguments about the early Jewish/Christian eschatological denotation of aiōnios are, in many ways, fundamentally anti-critical (or... anti-critically “fundamentalist”?).
There are two pieces of evidence from the New Testament that, to my mind, most clearly illustrate the poverty of this sort of revisionism.
The first, particularly relating to Ramelli and Konstan's proposal about aiōnios mainly denoting "pertaining to the age (to come)," can be challenged perhaps above all by Mark 10:29-30. In the NRSV, this reads

29 Jesus said, "Truly I tell you, there is no one who has left house or brothers or sisters or mother or father or children or fields, for my sake and for the sake of the good news, 30 who will not receive a hundredfold now in this age--houses, brothers and sisters, mothers and children, and fields with persecutions--and in the age to come eternal life.

The final words here are καὶ ἐν τῷ αἰῶνι τῷ ἐρχομένῳ ζωὴν αἰώνιον. For those with a knowledge of Greek, the serious problem here might also be realized: if, as Ramelli and Konstan suggest, aiōnios is to be understood as "pertaining to the age to come," then the saying of Jesus here is suggesting that his followers will receive "life of the age to come in the age to come"; and this is plainly redundant if not nonsensical. (Even if -- taking a clue from Ramelli and Konstan -- we were to gloss aiōnios not as the clunkier "pertaining to the age to come" but as the more concise "eschatological," this does little to relieve the problem here.)
On the other hand, that they will receive "everlasting life in the age to come" is perfectly concise and sensible.
To be sure, at several points in later NT and Jewish theology, eternal life and the eschatological age are integrally intertwined so as to almost bleed into each other (perhaps John 4:36?; cf. John 12:25 vis-a-vis Luke 20:34-36). (This would be an interesting study in its own right; though this is really just confined to usage in the Gospel of John -- and I think we should be careful to note that sometimes "eternal life" here seems to be a metonym for the eschatological age, not that zōē aiōnios life here itself means "eschatological life." Compare Matthew 25:46's εἰς ζωὴν αἰώνιον with John 5:24's μεταβέβηκεν . . . εἰς τὴν ζωήν? [εἰς ζωὴν αἰώνιον in John 4:14, 36; 6:27; 12:25?] Van der Watt 1989? Also, לחיי עולם. Allison: "appears on Jewish epitaphs [JIGRE 133; JIWE 1.81, 82, ...]" Cf. BS ii 120, 129, a threat to grave-disturbers to deny them μερος εις τον [βιον] αονιο[ν] [sic]? Sometimes חיי עולם as elliptical? Also, http://dtorah.com/otzashas_soncino.php?ms=Rosh-HaShana&df=16b: נכתבין ונחתמין לאלתר לחיי עולם.)
[John 3:36: "Whoever believes in the Son has eternal life; whoever disobeys the Son will not see life, but must endure God's wrath." John 12:25, "keep it" εἰς ζωὴν αἰώνιον? Compare John 6:27, "Do not work for the food that perishes, but for the food that endures for eternal life."]
https://www.reddit.com/UnusedSubforMe/comments/7c38gi/notes_post_4/dxbqlsb/
In any case, "everlasting/eternal life in the age to come" is clearly preferable in Mark 10 here, giving us a clear example of an early gospel text where aiōnios has a straightforward temporal denotation. (An instructive early Jewish example where we have a clear distinction between eternal life and the eschatological age might be found in Targum Pseudo-Jonathan on Jeremiah 51:39 and 51:57, where the unrighteous' being threatened with "eternal sleep" here in the original text of Jeremiah, שנת עולם, is interpreted/translated as that they will "die a second death and . . . not live in the age/world to come".)
The second piece of evidence for why this revisionisim re: aiōnios might be intrinsically implausible is that the author of Matthew (18:8), in taking over Mark 9:43, makes a stylistic change, substituting τὸ πῦρ τὸ αἰώνιον ("the eternal fire") for Mark's τὸ πῦρ τὸ ἄσβεστον ("the inextinguishable fire"): that is, substituting aiōnios in place of asbestos. We can only speculate as to why the author of Matthew felt compelled to make this particular change, though he does refer elsewhere to "inextinguishable fire" as Mark did, too (cf. 3:12, where it is used with κατακαίω, naturally evoking annihilation).
https://www.reddit.com/UnusedSubforMe/comments/7c38gi/notes_post_4/dyb9b0k/ (Worm, etc.)
A further look at the Markan source text reveals a nearby verse (9:48) that quotes Isaiah 66:24, and thus the Markan context has often been understood to suggest that those thrown into Gehenna will be tormented forever. There's been great debate over the exact meaning here. For example, in LXX Ezek 20:47 we find οὐ σβεσθήσεται referring to a fire that will ultimately produce annihilation.
I think that maybe above all here, the question of dispute is whether, in the Isaianic prooftext in Mark 9:48, "their worm" is a sort of metonym for torment or not. (This would be an interesting topic for a more thorough study. Perhaps also compare Gk. Apoc. of Ezra 1.24?: "Woe to the sinners in the world to come, for their condemnation is endless and the flame unquenched.") One thing that cannot be sustained, though, is the idea that this refers merely to corpses: this wouldn't fit the Markan context. And while we should exercise some caution here, several other texts that are influenced by Isa 66:24 -- whether influenced directly or indirectly -- assume to genuinely assume eternal torment in this: cf. Judith 16:17; and literal worms also play a part in the torment in Apocalypse of Peter X 25 and the Slavonic version of 3 Baruch 16.4; and there's a single "unsleeping worm" in Greek Apocalypse of Ezra 4.20f. (cf. Apocalypse of Abraham 31:3-5, too).
For other texts which build on Isa 66:24, cf. LAB 63:4; t. Ber. 5:31; b. Roš. Haš. 17a; 2 Clement 17:5-7; and see also the discussion of Tosefta Sanhedrin below. Much of this is discussed in greater detail in Part 8 of the series. (On a minor note, Mark 9:48 has present τελευτᾷ, σβέννυται instead of Isaiah's futures. Also, early scribes felt compelled to insert Mark 9:48's citation of Isaiah at Mark 9:44 and 9:46, too.) Also, a connection is forged between Isa 66:24 and Daniel 12:2, in their use of the dis legomenon דְּרָאוֹן. (The latter verse is the origin of Matthew 25:46.)
Yet that, in its context, the very prooftext in Mark 9:48 is employed to suggest a harrowing scenario for those who have a more-or-less complete bodily constitution -- as opposed to those who may have torn out an eye and yet will inherit the kingdom -- may more plausibly suggest (if only based on the heightened rhetorical impact here) that these people may indeed retain their limbs and eyes in the afterlife, and thus comport more with eternal torment and not annihilation. Interestingly, in several of the more prominent early Christian "tours of hell" (like in the Apocalypse of Peter), there's a focus on the torture of specific body parts of the unrighteous: cf. Czachesz's The Grotesque Body in Early Christian Discourse. Although there are certain idiosyncratic reasons why, in these later apocalypses, these appendages are singled out for specific attention, at the very least the idea in Mark may be that these appendages or are available for torment.
Perhaps more persuasively, though, Marcus (2009: 682) notes that

Dale Allison points out the similarity of this picture of eternal torment to that in the Greek myth about Prometheus, who was chained to a rock and had his liver devoured by an eagle. At night the liver would be restored, and the next day the eagle would devour it all over again

(ἧπαρ ἀθάνατον: cf. Hesiod, Theogony 524. This torment is described as occurring by "night" [when the liver regrows] and "day" [when the eagle eats it], which might be of some interest considering that the phrase "day and night" / "night and day" is somewhat stock in describing some forms of recurring torment: cf. IG XI,4 1299; Polybius 23.10; Punica 13.284f.; Revelation 14:11; 20:10 [the latter of which more directly have their source in Isaiah 34:10]; b. Terumah 150b in the Zohar (?). It's curious how many of these involve the Erinyes, the relevance of which will be discussed further soon. See also Hesiod, Works and Days: νῦν γὰρ δὴ γένος ἐστὶ σιδήρεον: οὐδέ ποτ᾽ ἦμαρ παύονται καμάτου καὶ ὀιζύος, οὐδέ τι νύκτωρ φθειρόμενοι, and my comment below.)
[For more on the idiom "night and day" in comparative context, cf. Martin West's The East Face of Helicon, 241 -- also including some comments on general phrases for "forever."]
There are several other connections with Prometheus that may be of interest. One is that the sin of the Watchers in 1 Enoch very closely parallels the instructions of Prometheus as described in Aeschylus, Prometheus Bound 441ff.
Excursus on the Location of Gehenna:
[Moved to a comment below, for space.]
Finally, the specific language βληθῆναι εἰς τὴν γέενναν, "to be cast into Gehenna," that we find in Mark 9:45 and 47 might remind us of the language we find elsewhere in Greek literature, referring to afterlife realms (of punishment): cf. the Titans, εἰς Τάρταρον ῥιφέντων (also Iliad 8.13f.). Above all we might look to Euripides, Orestes 264-65: μέθες: μί᾽ οὖσα τῶν ἐμῶν Ἐρινύων μέσον μ᾽ ὀχμάζεις, ὡς βάλῃς ἐς Τάρταρον: "Let me go! You are one of my Erinyes and have grasped me about the waist to hurl me into Tartarus." Here we have the use of βάλλω + ε(ι)ς Τάρταρον, just like Mark's βάλλω + εἰς τὴν γέενναν.
That the unrighteous will enter the “eternal fire” is once more mentioned in Matthew 25:41; and a few verses later (25:46), aiōnios is again used, this time to denote their punishment itself. In light of all these things, it can't be easily said that Matthew meant to convey a different concept (with τὸ πῦρ τὸ αἰώνιον in 18:8) than Mark did; and in fact although Matthew does not use the exact same vocabulary that Mark did, they appear to agree about the fate of the unrighteous.
(Among critical scholars, Dale Allison's "The Problem of Gehenna" attempts to mitigate these issues; but he does so almost exclusively by disassociating these sayings from the historical Jesus and/or by emphasizing the possibility that their original intention was one of exaggeration. Yet our primary interest here is in aiōnios itself; and philologically/lexicographically, Allison doesn't attempt any sustained argument that this should be understood in any sense other than "eternal.")
[Again, cf. Part 6 of my series for more on Matthew 25:46, and Part 8 on Mark 9:43f.]
Tradition Background and Synonyms of Aiōnios
From an academic history of religions perspective, eternity of afterlife torment can be found in various ancient Near Eastern and Indo-European traditions, as well as in Egyptian and both Hellenistic and non-Hellenistic Jewish traditions. Many people from these cultural/ethnic groups were demonstrably in contact with each other, lending each other details and schemata here (that is, specifically in terms of afterlife beliefs).
The extent to which early Christianity was particular influenced by Hellenistic and non-Hellenistic Jewish beliefs makes it highly likely that we should see early Christian beliefs—including those on the nature of afterlife punishments—in continuity with them, in various ways. While this doesn't suggest that Christianity slavishly reproduced the beliefs it inherited, from a critical perspective it does increase the likelihood that they would be similar; and, indeed—along with doctrines of annihilationism (which sometimes co-existed alongside eternal torment)—I think there's no question that we do see this.
Of course, there were a number of contemporary Greek and Jewish texts that hinted at the eternity/continuity of afterlife punishment, with various vocabulary used.
αἰώνιος punishment in (non-Christian) Greek lit., etc.:
Diod. S. 4.63.4; 4.69.5; (Pseudo-Platonic) Axiochus: "There too are persons licked round by wild beasts, and terrified by the torches of the Furies glaring around them; and enduring every kind of ignominious treatment, they are by everlasting/continual punishments worn down (αἰωνίους τιμωρίας κατατυραννοῦνται)"; Philodemus, On God 1.19, ταῖς αἰωνίοις ἀμοιβαῖς βασανισθησόμενοι πρὸς τῶν θεῶν.
[For more on Axiochus and Lucian's Menippus, here: https://www.reddit.com/UnusedSubforMe/comments/5crwrw/test2/dgeqxhs/]
As for other general compound phrases denoting neverending-ness that are parallel to similar phrases which actually use aiōnios itself, etc.: see Aeschylus, Ag. 1450: τὸν αἰεὶ . . . ἀτέλευτον ὕπνον, vis-a-vis the examples of "aiōnios sleep" I give in Part 3 of my series. Also, compare αἰώνιος ἀφθαρσία in Clement, What Rich Man Will Be Saved? 19.6 with ἀεί ἀθάνατον in Plato, Phaedrus 277a. (αἰώνιός νόμος καὶ τελευταῖος in Justin, Dial. 11?)
In direct conjunction: good examples in Plutarch, Non Posse 1106f.
With ἄφθαρτος: Chrysostom (Homily 27 on Genesis): "consider that before long [the unrighteous] will receive an immortal body [σῶμα ἄφθαρτον] of the kind that will have the capacity to undergo constant [διανεκῆ] and everlasting punishment [αἰώνιος κόλασιν]"; cf. also Mark 16:20 (extend version); Hebrews?
In terms of general equivalence, Keizer notes, on Philo, "For ἀθάνατος as an equivalent for αἰώνιος see . . . Ebr. 141 {27} and Mos. 2.14 {65} (text [19]). Cf. Aet. 75: μακραίων on a par with αἰώνιος. In Fug. 97 we have the single instance of ζωὴ ἀΐδιος in Philo's works." I'll discuss μακραίων later.
On things like Rom 16.25, χρόνοις αἰωνίοις, cf. my comments here; a la ἐξ ἀπείρου αἰῶνος (Plutarch?). Formally though, cf. Plato, χρόνον ἀπέραντον ("[have labored] forever"). BDAG also cites OGI 248, 54; 383, 10. And 383 has εἰς χρόνον αἰώνιον and εἰς τὸν ἄπειρον αἰῶνα. See also here, on Origen: https://www.reddit.com/UnusedSubforMe/comments/4jjdk2/test/d8l4ezf/.
More on Origen:

Similar terminology, such as ‘eternal punishment’ (αἰώνιος κόλασις),²⁵ or ‘incurable punishments’ (ταῖς ἀνηκέστοις κολάσεσιν) is also used.²⁶ Authority is certainly scriptural, since prophets ‘uttered many threats about the eternal punishment [περὶ τῆς αἰωνίου κολάσεως]’ and the Gospel refers to the ‘Gehenna and the other endless tortures’ (ἀτελευτήτων βασάνων).²⁷

See also ...ὀπισθότονον ἀνίατον, "in Deuteronomy the Word threatens with incurable lockjaw those who forsake godliness."
Juxtaposition: Chrysostom, ἡ βασιλεία αὐτοῦ βασιλεία αἰώνιος καὶ ἡ ἐξουσία αὐτοῦ εἰς γενεὰς καὶ γενεάς
Aristotle: ἀΐδιος γὰρ βασιλεία ἄνισος, ἐὰν ᾖ ἐν ἴσοις.
ἀνάπαυσιν καὶ αἰωνίαν?
καὶ ὅτι αἰώνια καὶ ἀτελεύτητα τὰ ἑκατέροις ἀποκείμενα
In addition to the adjective aiōnios, other words were used in conjunction with or to denote the eternality of punishment.
We might first start here with some notes on

• ἄφθαρτος/ἀφθαρσία. Shockingly, re: this adjective (and as a counterargument against aiōnios), universalists have occasionally suggested that "we never read of incorruptible punishment" (Daniel Livermore). But seeing to what extent ἄφθαρτος is applied exclusively to material things, I think it'd be more surprising if we ever did find it in reference to the abstract/immaterial state of punishment itself -- though cf. below on ἀθάνατος. (Similarly, ἄσβεστος isn't applied to punishment itself but to, say, fire that punishes.)

Yet here, as cited above, Chrysostom indeed uses ἄφθαρτος to refer to the imperishability/immortality of the resurrection body, and therefore the capacity of this to experience "constant [διανεκῆ] and everlasting punishment [αἰώνιος κόλασιν]" (Homily 27 on Genesis). Further, for good measure, just for the general synonymy, we might also look toward Justin Martyr for several examples of the use of ἄφθαρτος in parallel with aiōnios (and also, here, with punishment).
Probably the absolute most instructive text here is 1 Apol. 52:

τὴν δὲ δευτέραν, ὅταν μετὰ δόξης ἐξ οὐρανῶν μετὰ τῆς ἀγγελικῆς αὐτοῦ στρατιᾶς παραγενήσεσθαι κεκήρυκται, ὅτε καὶ τὰ σώματα ἀνεγερεῖ πάντων τῶν γενομένων ἀνθρώπων, καὶ τῶν μὲν ἀξίων ἐνδύσει ἀφθαρσίαν, τῶν δ’ ἀδίκων ἐν αἰσθήσει αἰωνίᾳ μετὰ τῶν φαύλων δαιμόνων εἰς τὸ αἰώνιον πῦρ πέμψει.

[Translation later; see Part 6 of this post.]
In Justin's Dial. 117 we find

...ὅταν πάντας ἀναστήσῃ, καὶ τοὺς μὲν ἐν αἰωνίῳ καὶ ἀλύτῳ βασιλείᾳ ἀφθάρτους καὶ ἀθανάτους καὶ ἀλύπους καταστήσῃ, τοὺς δὲ εἰς κόλασιν αἰώνιον πυρὸς παραπέμψῃ

Here, those saved are made imperishable [ἄφθαρτος] and immortal [ἀθάνατος] and painless [ἄλυπος] in an eternal [aiōnios] and incorruptible/indissoluble [ἄλυτος] kingdom, while their counterparts are sent to the eternally [aiōnios]-punishing fire. Further, in Dial. 45, we find the same three of adjectives as in Dial. 117 used to describe the condition of the saved in the kingdom, while others are "sent into judgment and condemnation of fire to be punished unceasingly [ἀπαύστως]":

ὅταν οἱ μὲν εἰς κρίσιν καὶ καταδίκην τοῦ πυρὸς ἀπαύστως κολάζεσθαι πεμφθῶσιν, οἱ δὲ ἐν ἀπαθείᾳ καὶ ἀφθαρσίᾳ καὶ ἀλυπίᾳ καὶ ἀθανασίᾳ συνῶσιν

(Tying some of these together, cf. again 1 Apol. 52. Also, the immortality of those consumed by "unceasing [ἄπαυστος] fire" is explicit in Dialogue 100, both of which I've discussed in more detail here.)
Finally, for a direct conjunction of ἄφθαρτος and aiōnios, in Dial. 139, we read of believers who τὰ αἰώνια καὶ ἄφθαρτα κληρονομήσειν.
In any case: more in terms of words used to directly denote the eternality of punishment:

• ἄπαυστος (Justin, Dial. 45; cf. 100 applied to fire itself; two occurrences here; similarly, Anastasius the Sinaite: κλαυθµὸς ἄπαυστος [grouped with ὀδύνη αἰώνιος, λύπη ἀτελεύτητος, βρυγµὸς ἀσίγητος, etc.])
  
• ἀθάνατος (Diod Sic 8.15; Philo, Spec. 3.84; Josephus, BJ 2.153; Sib. Or. 2.332; Basil [Homilia in Sanctum Baptisma] and John of Damascus, ἀθάνατα βασανίζομαι; Evagrius: Καταναλωθήσεται πᾶς ἁμαρτωλὸς ὑπὸ τοῦ αἰωνίου πυρὸς καὶ οὐ δύναται τελευτῆσαι· ἀθάνατα γὰρ βασανισθήσεται.)
  

For more on immortalization for punishment see Part 8 on Justin. Some suggest, in Revelation 20:14,

unbelievers formerly held in the temporary bonds of "Death and Hades" will be handed over to the permanent bonds of the Lake of Fire.

• ἀΐδιος (Pseudo-Plato, Axiochus 372; Josephus, BJ 2.163; AJ 18.14; Hippolytus, Adversus Graecos 2 [ἀϊδίου κολάσεως], 3; cf. discussion of 4 Macc 10:15 in Parts 3 and 4)

De Universo / Οrationis ad Ηellenes:

Ἧς φωνῆς τὸ ἀνταπόδομα ἐπ' ἀμφοτέροις τὸ δίκαιον ἐπάγει· τοῖς μὲν εὖ πράξασι καὶ δικαίως τὴν ἀΐδιον τῶν ἀγαθῶν ἀπόλαυσιν παρέχον, τοῖς δὲ τῶν φαύλων ἐργάταις, τὴν ἀΐδιον κόλασιν ἀπονέμον· καὶ τούτοις μὲν τὸ πῦρ ἄσβεστον διαμένει. Σκώληξ δέ τις ἔμπυρος μὴ τελευτῶν, μηδὲ σῶμα διαφθείρων, ἀπαύστῳ ὀδύνῃ ἐκ στόματος ἀναβράσσων παραμένει.

• ἀδιάλειπτος (Josephus, BJ 2.155; see also Romans 9:2, where ἀδιάλειπτος ὀδύνη means "constant/unceasing distress/pain.")
  
• ἀτέλεστος/ἀτελεύτητος: περὶ γεέννης καὶ τῶν ἄλλων ἀτελευτήτων βασάνων, Origen. Cf. Irenaeus, Adv. Haer. 5.27.2, where it clearly functions as a synonym of aiōnios as "never-ending"; Gk. Apoc. of Ezra 1.24 (actually paralleling ἄσβεστος); John of Damascus, De fide orthodoxa 2.1; Man. 2.36. More patristic stuff here. Apostolic Constitutions 5.7?
  
• More on ἄσβεστος: https://www.reddit.com/UnusedSubforMe/comments/7c38gi/notes_post_4/dyb9b0k/. See also Judith 16:17; and the verbal οὐ σβέννυμι (and Hebrew Vorlage) too. Isa 34:10: https://www.reddit.com/UnusedSubforMe/comments/8i8qj8/notes_5/dysu6h0/.
  

Google Books: "Οrationis ad Ηellenes"
De Universo; Πρὸς Ἕλληνας καὶ πρὸς Πλάτωνα ἤ καὶ περὶ τοῦ παντός; Cohortatio ad Graecos?
In the Orthodox Triodion, cf. the Synodikon: ἡ κόλασις ἀτελεύτητος καὶ ἡ βασιλεία ἀΐδιος. More here.

• συνεχής (Philo, De Cherubim 1.2)
  
• ἀπέραντος (Justin, Apol. 28, τὸν ἀπέραντον αἰῶνα; ἀπέραντος τιμωρία || αἰώνιος τιμωρία (Hippolytus Ad Hellenes De Causa Universi (?))
  
• ἀκατάλυτος (4 Macc 10:11: "because of your impiety and bloodthirstiness, will undergo unceasing torments"); Chrysostom, De Lazaro 6.6. Cf. also Hebrews 7.16-17, and εἰς τὸν αἰῶνα?
  
• ἄπειρος (Plutarch, interpreting a saying of Pindar that uses ἄπειρος [τὸν ἄπειρον . . . σκότον], uses this to paint a picture of afterlife κολάσματα σκυθρωπά. In De infantibus, Gregory of Nyssa -- describing the fate of Judas, according to what's said in Matthew 26:24 -- writes that because of Judas' great evil εἰς ἄπειρον παρατείνεται ἡ διὰ τῆς καθάρσεως κόλασις. Re: this passage, however, Ramelli notes that "if its end is purification and not retribution, this κόλασις cannot endure eternally," and thus translates εἰς ἄπειρον here as "to an indefinite duration." This would seem to be true, though I think we need a more precise understanding of ἡ διὰ τῆς καθάρσεως κόλασις. Cf. also ἄπειρον αἰῶνα (cf. κόλασις εἰς ἀπείρους αἰῶνας, Chrysostom, and later Olympiodorus; εἰς τὸν ἄπειρον αἰῶνα, Antiochus of Commagene.)
  
• ἄληκτος (First and foremost we might think of Ἀληκτώ, Alecto, one of the Erinyes, discussed elsewhere here. Beyond this, cf. the ἄληκτον ὀδυρμόν in Gregory of Nyssa, Adversus eos qui castigationes aegre ferunt [Against Those Who Hardly Tolerate Reproaches]. Ramelli writes here that "those who are suffering are continually lamenting, but it is not eternal proper," citing 3 Macc 4:2: τοῖς δὲ Ιουδαίοις ἄληκτον πένθος ἦν καὶ πανόδυρτος... Ramelli: "It is uninterrupted while it lasts, but it does not mean that it will last eternally.")
  
• In Cyril's Commentarii in Lucam we find διηνεκὴς ἡ κόλασις, "continuous/perpetual punishment." (For διηνεκής as a synonym of αἰώνιος, see Part 8 of my post series, on Clement, What Rich Man Will Be Saved? 19.6. See also the first section above on Chrysostom, Homily 27 on Genesis.)
  
• ἀνήνυτος and ἀτελής in pseudo-Plato, Axiochus 371-372?
  
• διηνεκής (Chrysostom, Homily 27 on Genesis; for "darkness" in De Universo etc.)
  

and

• ἀπαραίτητος, used at least for general (though I'm not sure if eschatological/afterlife) punishment
  
• ἀκάματος: Sib. Or. 2.336
  
• ἄφυκτος, Athanasius (PG) 26.664??
  

Adverbial phrases? οὔποτε ἐκβαίνουσιν (from Tartarus) in Plato
Theodoret: ἀεὶ τιμωρίας
For other phrases denoting neverending-ness which don't necessarily suggest punishment itself cf. ἤματα πάντα (Hom. Hymn to Dem. 367.)
οὐ παυθήσεται, Justin variant of Isa 66.24
Other words used to denote neverending-ness -- again, not necessarily used to refer to punishment -- include διατελής; ἀνήνυτος [though cf. below on the last word here]; ἀμάραντος; and for phrases see οὐκ ἐκλείψει ἔτι in Psalms of Solomon 3.
ἄλυτος in Sophocles, Electra? τάδε γὰρ ἄλυτα κεκλήσεται, οὐδέ ποτ᾽ ἐκ καμάτων ἀποπαύσομαι ἀνάριθμος ὧδε θρήνων.
As for aiōnios and related terms on the Jewish side, there are things like Philo, De Cher 1.2:

He who is sent away [ἀποστελλόμενος] is not prevented from eventually returning, but he who is cast out [ἐκβληθεὶς] by God undergoes eternal exile [τὴν ἀίδιον φυγὴν ὑπομένει]. For the former, who is not yet firmly in the grasp of evil, is allowed, if he repents, to return to virtue as to a homeland from which he was driven; but the latter, oppressed and constrained by a violent and incurable [ἀνίατος] disease, is forced to carry the undying sufferings forever [φέρειν ἀνάγκη τὰ δεινὰ μέχρι τοῦ παντὸς αἰῶνος ἀθάνατα], contemptuously dismissed to the "place of the impious" to endure a full dose of unremitting misery [ἄκρατον καὶ συνεχῆ βαρυδαιμονίαν ὑπομένῃ; or to endure unrelieved and continuous misery]

. . .

αὖθις δὲ κατὰ τὸ παντελὲς ἀνεπάνακτος/ἀνέπακτος ἐκβάλλεται
but the second time [Hagar] is thrown out definitively [κατὰ τὸ παντελὲς], never to return

(Some good commentary on this: http://torreys.org/sblpapers2017/3Commentary_1-10.pdf ; see especially ἀσεβῶν χῶρον, used again in Congr. 57 and also by Josephus and Lucian, etc.)
and 4 Macc 12.12:

ἀνθ' ὧν ταμιεύσεταί σε ἡ δίκη πυκνοτέρῳ καὶ αἰωνίῳ πυρὶ καὶ βασάνοις, αἳ εἰς ὅλον τὸν αἰῶνα οὐκ ἀνήσουσίν σε.
Because of this, justice has laid up for you intense and eternal fire and tortures, and these throughout all time will never let you go (NRSV)

Also (with Steve Mason commenting on Josephus),

[f]or similar phrases to “deathless retribution” (here ἀθάνατον τιμωρίαν), see [BJ] 2.155 (of Essenes) and 2.163 (of Pharisees).

(And cf. Philo, Spec. 3.84—τὸ τῆς τιμωρίας ἀθάνατον—and the use of ἀδιάλειπτος in BJ 2.155; AJ 18.14, on the Pharisees’ belief “that souls have power to survive death and that there are rewards and punishments under the earth for those who have led lives of virtue or vice; eternal imprisonment [εἱργμὸν ἀίδιον] is the lot of evil souls, while the good souls receive an easy passage to a new life.” Cf. also Justin, Apol. 20 here.)
Rabbinic (and Other Jewish) Texts on Gehenna
Further, in Tosefta Sanhedrin (13), the eschatological categorization of the school of Shammai is delineated, which follows that of Daniel 12:2 (the good vs. the totally unrighteous, רשעים גמורים)... except for that third category is also added, who יורדים לגיהנם ומצפצפים ועולים ומתרפאים (honestly I'm unsure what מצפצפים signifies, though it likely derives from צפצף as "to press" here; but if it suggests some vocal emanation, cf. Plato, Phaedo 113, discussed below). After this, it's said that "the transgressors of Israel and the transgressors of the heathen who are in the world" בגופן יורדין לגיהנם and, after twelve months, are annihilated (cf. also Seder 'Olam and Pesikta de-Rav Kahana).
Directly following in t. Sanhedrin, however, it's explicitly said that for a particular class of unrighteous, גיהנם ננעלת בפניהם ונדונין בה לדורי דורות: “Gehenna is closed up after them, and they are condemned in it forever and ever.” This is "proven" by a quotation of Isaiah 66:24 -- which, as we have noted, uses the word דְּרָאוֹן (cf. נדונין) -- after which it is said שאול כלה והם אינם: "Sheol wastes away, but they do not (waste away)," citing Ps 49:14 for this. B. Rosh Hashanah. 17a is nearly identical to the Tosefta here; and, again, Seder 'Olam 3, too (גיהנם ננעלת בפניה ונידונין בתוכה לעולמי עולמים).
[Cf. Flusser et. al: https://www.reddit.com/AcademicBiblical/comments/33yj14/%CE%B1%E1%BC%B0%CF%8E%CE%BD%CE%B9%CE%BF%CF%82_ai%C5%8Dnios_in_jewish_and_christian/ctocgj9]
(B. Roš. Haš. 17a also has the very intriguing line: גיהנם כלה והן אינן כלין. If anything I think this might be compared with some traditions from 1 Enoch. [It continues after this that (תהלים מט) וצורם לבלות שאול (מזבל לו). See more here.] Also, as a minor note, just shortly after this in 17a, compare the prediction that the people of Sura [מחוזא] will be called בני גיהנם, "sons of Gehenna," with υἱὸν γεέννης, "son of Gehenna," in Matthew 23.15.)
In b. Eruvin 19a, Simeon ben Lakish states רשעים אפילו על פתחו של גיהנם אינם חוזרין בתשובה: "the unrighteous do not turn back in repentance even at the entrance of Gehenna," with again Isa 66:24 as a prooftext. Resh Lakish argues that the use of הפושעים and not שפשעו in Isa 66:24 is significant, suggesting that their rebellion actually lasts לעולם. In b. Pesachim 54a, Isa 66:24 is simply a prooftext for the everlastingness of the fire of Gehenna (אור דגיהנם) itself:

...[רבי יוסי אומר אור שברא הקב"ה בשני בשבת אין לו כבייה לעולם שנאמר [ישעיהו סו, כד

But subsequent to this in b. Eruvin (19a), we read that even for the unrighteous, אברהם אבינו ומסיק להו ומקבל להו בר מישראל שבא על בת עובד כוכבים דמשכה ערלתו ולא מבשקר ליה: "our father Abraham comes, brings them up, and receives them, except such an Israelite as had immoral intercourse with the daughter of an idolater, since his foreskin is drawn and so he cannot be identified/recognized [as a Jew]."
PART 1 CONTINUED HERE
Note: I've moved another section that was originally in the body of this post -- on Gehenna and other eschatological punishment traditions involving fire and destruction -- to a comment below.