Green’s Dictionary of Slang

hopper-arsed adj.

also hopper-hipped, -rumped, -tailed
[SE hopper + -arsed sfx]

large-buttocked.

[UK]Middleton Women Beware Women II ii: Her skin must be both white and plumped, / Her body straight, not hopper-rumped.
[UK]Mercurius Fumigosus 3 14-21 June 4: She was Beetle-brow'd, Monkey-proud, Leathern-Ear'd, Hawkes-nos'd, Wry-mouth'd, Crump-backt, Hopper-arst, Splay-footed.
[UK]Wycherley Love in a Wood II i: Moreover she is bow-legg’d, hopper-hipp’d [...] and has a Complexion like a Holland cheese.
[UK]B.E. Dict. Canting Crew n.p.: Hopper-arst, when the Breech sticks out.
[UK]W. King York Spy 58: I’m a Limb Trimmer by Trade, celebrated for bolstering and padding up the Hump-back’d, Hopper-ars’d Young City Beaus, into compleat Gentlemen.
[UK] in D’Urfey Pills to Purge Melancholy VI 351: There’ll be hopper-arsed Nancy, / And Sarey fac’d Jenny by Name.
[UK]Grose Classical Dict. of the Vulgar Tongue n.p.: Hopper-arsed. Having large projecting buttocks: from their resemblance to a small basket, called a hopper or hoppet, word by husbandmen, for containing seed corn, when they sow the land.
[UK]J. Bell Jr. (ed.) Rhymes of Northern Bards 45: There was knack knee’d Mat, wiv’s purple suit, / An hopper-a—s’d Dick.
[UK]Egan Grose’s Classical Dict. of the Vulgar Tongue.
[US]Randolph & Wilson Down in the Holler 254: hopper-tailed: adj. Having broad or prominent buttocks.