wanna back that up with a fist Share definition Flag sumthing u say to a douche who is talkin shit and cant back it up, a.k.a 7-2 gay wanna back that up with a fist ill stab u wench ahhh im sorry wanna back that up with a fist by Anonymous May 22, 2003 0 0 Get merch Get the wanna back that up with a fist mug. Buy Now — $32.95 See more merch