The noun ass has 4 senses (first 2 from tagged texts)
1. (3) 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, ass -- (the 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?")
2. (1) ass -- (a pompous fool)
3. ass -- (hardy and sure-footed animal smaller and with longer ears than the horse)
4. fuck, fucking, screw, screwing, ass, nooky, nookie, piece of ass, piece of tail, roll in the hay, shag, shtup -- (slang for sexual intercourse)