Open English Wordnet
Nouns
(n)buttocks, nates, arse, butt, backside, bum, buns, can, fundament, hindquarters, hind end, keister, posterior, prat, rear, rear end, rump, stern, seat, tail, tail end, tooshie, tush, bottom, behind, derriere, fanny, assthe fleshy part of the human body that you sit on“he deserves a good kick in the butt”, “are you going to sit on your fanny and do nothing?”
Adjectives
(s)grim, inexorable, relentless, stern, unappeasable, unforgiving, unrelentingnot to be placated or appeased or moved by entreaty“grim determination”, “grim necessity”, “Russia's final hour, it seemed, approached with inexorable certainty”, “relentless persecution”, “the stern demands of parenthood”