adj. "sicky-nar-nar" or "sicky-nar" is used to describe something that blew your mind, rocked your world, or otherwise kicked-ass.
It is derived from the common words "sick" and "gnarly" and is most often used to describe a dangerous trick on something with wheels or a board, or to describe a social function where everbody got wasted.
If you are the first to use this word in your group of friends, it is customary to charge others a dollar for the use of the word once they have heard it.
"Dude, did you see Matt pull off that backflip? It was sicky-nar-nar."
"That party was sicky-nar." "Dude, you owe David five bucks now."