Butt flannel Share definition Flag A piece of cloth used specifically to wipe and clean your anus whilst washing yourself. The rest of my family may use it on their faces, but you’re actually holding my butt flannel. Butt flannel by dirk-diggler69 June 30, 2021 0 0 Get merch Get the Butt flannel mug. Buy Now — $32.95 See more merch