what tha duce Share definition Flag WHAT DA FUCK!!!...mainly used by stewie from "family guy" JOSEPH:brah, that cat is cute! NANDO: WHAT THA DUCE!!! what tha duce by !!NeRD!! June 20, 2006 0 0 Get merch Get the what tha duce mug. Buy Now — $32.95 See more merch