manass Share definition Flag Any ass that appears to be that of the human male. Mostly used as a term for a female having a narrow, squarish, semi-flat buttocks. Lindsay Davenport, apart from being an incurable swamp donkey, has a most egregious case of manass. manass by pdad September 25, 2005 0 0 Get merch Get the manass mug. Buy Now — $32.95 See more merch