"Croupon, catastrophe, stern-works, toby, truck-end"

David Crystal considers whether it is anachronistic to see a pun on Bottom in Midsummer Night's Dream -- the answer (to my mind, a little surprisingly) is that it is. Crystal lists the attested synonyms for "buttocks" in various historical periods:

1000s: arse
1200s: cule, latter end, fundament, buttock
1300s: tut, tail, toute, nage, tail-end, brawn, bum
1400s: newscher, croupon, rumple, lend, butt, luddock, rearward, croup
1500s: backside, dock, rump, hurdies, bun, sitting-place, prat, nates, crupper, posteriorums,
1600s: cheek, catastrophe, podex, posterior, seat, poop, stern, breek, flitch, bumfiddle, quarter, foundation, toby
1700s: rear, moon, derriere, fud, rass, bottom
1800s: stern-post, hinderland, hinderling, ultimatum, behind, rear end, hinder, botty, stern-works, jacksy,
1900s: sit, truck-end, tochus, BTM, sit-upon, bot, sit-me-down, fanny, beam, ass, can, keister, batty, bim, quoit, rusty-dusty, twat, zatch, booty, bun, tush

 Re "botty" / "batty" see also Geoff Pullum's old post on the term "batty man" and homophobia in the Caribbean. Re "twat" and "fanny" -- I wonder what the criteria are for euphemisms to become ambiguous in this way -- I had honestly never thought of the former as potentially ambiguous, but here is the OED:

1964    M. Kelly March to Gallows xii. 132,   I could tell her what to do with her twat if she's frightened to sit on it.