The fleshy part of the human body that you sit on - nates, butt, backside, bum, buns [N. Amer], can [N. Amer], fundament, hindquarters, hind end, posterior, rear, rear end, rump, stern, seat, tail, tail end, tooshie, tush [N. Amer], bottom, behind, derriere, heinie [US], derrière
Noun: buttockbútuk
Either of the two large fleshy masses of muscular tissue that form the human rump - cheek