The acronym for the phrase 'Fuck It I'm Young'. It's infinitely better than YOLO and much easier to pronounce, obviously.
by Steven. Just Steven. August 17, 2012
Jimmy: I dunno man, do you really think you should fuck this dead hooker we found here in the forest
Billy: FIIY
Jimmy: Hmm didn't think of it like that, Seems legit
Billy: FIIY
Jimmy: Hmm didn't think of it like that, Seems legit
by SmilesNLulz May 27, 2012
by Bethany-Ruth July 07, 2012