Douche Manure Share definition Flag Is a person who thinks they are the shit, when in fact they are a piece of shit and a douche to boot. Mortimer: Hey guys I just got 1600 on my SATS. Me: Shut up Mort, you Douche Manure. Douche Manure by Mountain Dewche April 15, 2009 0 0 Get merch Get the Douche Manure mug. Buy Now — $32.95 See more merch