The fleshy part of the human body that you sit on - buttocks, 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, heinie [US], derrière