different between buttocks vs bumsters

English

buttocks

plural of buttock.
- 1707, Thomas Brown, "Moll Quarles's Answer to Mother Creswell of Famous Memory" in The Second Volume of the Works of Mr. Tho. Brown, containing Letters from the Dead to the Living both Serious and Comical, part three, page 184:
  At lea?t five Hundred of the?e reforming Vultures are daily plundering our Pockets, and ran?acking our Hou?es, leaving me ?ometimes not one pair of Tractable Buttocks in my Vaulting-School to provide for my Family, or earn me ?o much as a Pudding for my next Sundays Dinner : [...]

bum +? -ster +? -s

bumsters pl (plural only)

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