booty brownie Share definition Flag shit...A large peice of shit that smells like yo mamas bathroom when uncle Joe uses it... EWWW!!!! Someone took a hella big booty brownie and didn't flush! booty brownie by $pyd@m@n3 November 13, 2007 0 0 Get merch Get the booty brownie mug. Buy Now — $32.95 See more merch