FACK Share definition Flag Basically a word that roadmen use instead of “fuck” because inevitably it just sound so much better when you say it like that. “Oi you alright mate?” “Fack off Jimmy” FACK by XxyourmumgayxX April 19, 2019 0 0 Get merch Get the FACK mug. Buy Now — $32.95 See more merch