duff

the part of the body upon which someone sits I've been sitting on my duff all day Synonyms backside, behind, booty (also bootie) [slang], bottom, breech, bum, buns, butt, caboose, can, cheeks, derriere (or derrière), buttocks, fanny, fundament, hams, haunches, heinie [slang], hunkers, keister (also keester) [slang], nates, posterior, rear, rear end, rump, seat, tail, tail end, tush [slang]Related Words beam, stern; moon [slang]