F.B.U.I. Share definition Flag An acronym which stands for Face booking under intoxication. Did you see that booze hound on Face book? It's obvious that she's drunk and she's not even 21. She's gonna get a F.B.U.I. one day. F.B.U.I. by F.B.U.I. March 27, 2010 0 0 Get merch Get the F.B.U.I. mug. Buy Now — $32.95 See more merch