As the title said, how (if it is indeed possible) would one add a neologism, created on the spot, to an existing language?
Could it be done by using it, spreading it around, and hoping it catches on? Is there a better way? Could bribing the various dictionary publishers help (what are the chances of a word catching on just because it’s in the dictionary)?
For explanation’s sake, I’ve come up with the following word from (badly used) Greek root words;
In English, it’s impossible. Words are accepted by the leading authorities by virtue of common and sustained use.
If you can get people to start using your word - and, in this case, you won’t - then it will eventually become an accepted word. There’s no other way.
Read the line that immediatly follows that one?
I think you would have more luck with the word “addinga”.
Bisected8, “fetch” is not happening.
Stranger
You could submit it to the Urban Dictionary.
Log on to urbandictionary.com
post your word
let the masses decide by either giving it a thumbs up or thumbs down. If you get enough thumbs up, you win, and it’s a word.
To be honest I’d rather gnaw off my own hand and stick the bloody stump in the toilet than visit Urban Dictionary again…
That’s an awfully violent reaction for just visiting a website. It’s a pretty useful tool actually. What’s your beef with them?
I don’t have anything against them, it’s just that I know I’ll spend hour and hours reading through entries on it. I have enough of that with TV Tropes and wikipedia, ty. 
It’d be very easy if you got someone like Mr Obama or Oprah to use the word. Then everyone would start and within a year it’d be in the dictionary.
Again it’s now what you know but who
I can understand it. I tend to come away from any visit to Urban Dictionary feeling totally grossed out either by the disgusting sexual practices described, or the profound misogyny (or, usually, both). Useful sometimes, yes (though I think a lot less reliable than Wikipedia), but not pleasant.
I once read that the word “quiz” was introduced into the language by a Dublin publican, on a bet that he introduce a new word overnight. He then spent the night chalking QUIZ in large letters on walls all over the city. The next day everyone was asking questions about it, and “quiz” came to mean…
It probably isn’t true (and I may have remembered some of the details wrong), and even if it is, I doubt that it would work today, but it is kind of a nice story, that has stuck with me for many years. Does anyone else know anything about it?
In your case:
Get a PhD. in sociology.
Write an academic paper on the subject, which includes an explanation of the neologism.
Publish the paper in a respected peer-reviewed publication.
Have other academics quote your paper - and use your word - in *their *papers.
Wait a few years until it becomes the accepted term.
If you can convince people that aren’t friends or family to use the word regularly (and when you’re not around), then I think you can safely say it’s become a cromulent neologism. 
Go to Dublin, hire all the street urchins in to chalk it on the walls all over the place overnight. In the morning everybody will be talking about it, asking each other “What does this new word mean?”
I grok that only a muggle would come up with such a scheme. It would never ever occur to a hobbit, for example.
What a perfectly cromulent idea! It embiggens* my heart just contemplating it.
(*Technically not a neo- but more like a reneo-.)
Renovatude.