fank ass Share definition Flag A term used to describe a shady or corrupt character. Someone who goes around dealing scams, stealing & lying just to achieve a personal goal. " I can't believe how much of a fank ass your brother has become, Michelle" said Tommy. fank ass by SxychryGrly July 17, 2016 0 0 Get merch Get the fank ass mug. Buy Now — $32.95 See more merch