Take your pick.
flock, sens, mickle, arse, keister, thunder mug, pile, stern, lavatory, stool, potbelly, butt, fecal matter, crapper, commode, throne, skunk, bay window, tooshie, lav, derriere, can buoy, gutter, seat, weed, pot, heap, hind end, kitty, sess, behind, smoke, tin can, lot, passel, slew, faeces, ass, sewer, deal, quite a little, toilet, faecal matter, locoweed, peck, sight, wad, posterior, potty, bathroom, ordure, grass, rear end, tush, good deal, flowerpot, chamberpot, canful, toilette, can, john, chiffonier, green goddess, nates, batch, rump, stack, mess, spate, rear, bottom, buns, potful, corporation, tail, fundament, mountain, plenty, potentiometer, mint, dope, buttocks, raft, jackpot, fanny, hindquarters, mass, bum, tidy sum, backside, hatful, tin, prat, gage, tummy, feces, privy, great deal, dejection, tail end, muckle
fanny, privy, tail, can buoy, prat, butt, flush toilet, bathroom, washbasin, tin, tin can, can, nates, bottom, toilette, earth-closet, potty, fundament, outhouse, crapper, posterior, washstand, washbowl, behind, whoremaster, stern, commode, backside, bum, john, whoremonger, buns, stool, hindquarters, tail end, derriere, basin, throne, rear end, trick, hind end, rump, buttocks, toilet, bath, keister, lavatory, sewer, ass, gutter, arse, lav, rear, tush, jakes, canful, seat, pot, tooshie
