A neologism, for those not in the loop, is, according to wikipedia,
"... a word, term, or phrase which has been recently created ("coined") —often to apply to new concepts, or to reshape older terms in newer language form. Neologisms are especially useful in identifying inventions, new phenomena, or old ideas which have taken on a new cultural context.
Neologisms are by definition "new," and as such are often directly attributable to a specific individual, publication, period or event. The term "neologism" was itself coined around 1800; thus for some time in the early 19th Century, the word "neologism" was itself a neologism. It can also refer to an existing word or phrase which has been assigned a new meaning."
So here's one of me very own:
Juxtaprose (n): a piece of writing littered by vocabulary so advanced and arcane, that most of what is said, is rendered unintelligible.
For other arb but interesting newbie-words, click on www.wordspy.com