“Twas brillig, and the slithy toves
Did gyre and gimble in the wabe;
All mimsy were the borogoves,
And the mome raths outgrabe.”
A great setting that real words might not be able to define.
Burgess’s Nadsat slang in The Clockwork Orange is very scene setting and is at least partially made up by the author.
Sounds like it’d be related to the Crushstacean, a giant crab in Brian Clevinger’s Nuklear Age.
Another one I remembered: “Mathom”, from Lord of the Rings. It’s a Hobbitish word for an old trinket that doesn’t really have much use but you keep around anyway, the sort of thing that gets passed around extensively as a present.
The XKCD guy bitched about the made-up words in Anathem, but he’s full of beans. It was well done, and I wouldn’t be surprised if some of that language makes it into the general vocabulary. He’ll be our generation’s Heinlein.
gorram from the Firefly writers.
Humorist Gelett Burgess (who wrote The Purple Cow) is responsible for the adoption of blurb as a synonym for “publicity” or “testimonial”.
Humpty Dumpty explains to Alice that “slithy” is made up of “slimy” and “lithe” – two words packed together “like a portmanteau.” And “portmanteau,” meaning a composite word like “brunch,” has actually entered the language (“slithy,” not so much).
George Carlin paraphrase: I hate it when people say “use your own words” I’d prefer to use the same words everyone else is using.
That reminds me of the Calvin and Hobbes wherein Newton’s First Law of Motion is described - in Calvin’s own words - as ‘Yakka foob mog. Grug pubbawup zink wattoom gazork. Chumble spuzz.’
see this discussion, too.
I saw the word blow-jobby and I thought, "we tend to put ‘ish’ and ‘y’ at the end of anything to make it an adjective… and a new word. Or does that not count?
Was George Orwell the first to use doublespeak and the like in his 1984 ?
No one invented doublespeak. There has always been doublespeak.
Doublethink, but Newspeak - no comparatives or superlatives (use “plus” and “doubleplus”) and “un-” prefix rather than independent negatives. Thus “good, better, best, bad, worse, worst” becomes “good, plusgood, doubleplusgood, ungood, plusungood, doubleplusungood”.
The book title, btw, was Nineteen Eighty-Four - words, not figures. 
Shall we indulge in rishathra?
(Scroll to p. 170.)
And it was published in Nineteen Forty-Eight.
One of my psych professors slipped a question into one of his study guides early in the term that was along the lines of “Is schizophrenia a karass or a granfalloon? Explain.”
I thought, “Cool. Vonnegut joke,” and thought that maybe he wasn’t going to be so boring after all.
Imagine my dismay when, at the next class meeting, it turned out that less than a quarter of the class had read any Vonnegut, and the professor proceeded to belabor the point with excruciating awkwardness. He even used the terms on the midterm exam.
I think about half of my class is irrationally prejudiced against Vonnegut now. 
Remembered another one: “Ansible”, meaning a faster-than-light communication device, as coined by Ursula K. LeGuin (and subsequently used by many other SF writers, including Orson Scott Card).
You have insufficient bodily openings.
Indeed satirist John Clarke invented not just new words but an entire sport - Farnarkling.
Plenty of written commentary about Dave Sorenson and the sport of Farnarkiling is around and is well worth digging up.
Yabbut from about the mid 1930s it was called doubletalk, and still is in not-so-literary circles.
Now tell me who first used yabbut.
I feel that I must clarify at this point that I, personally, have never dated outside of my species.