bunion: [18] Bunion is probably a modification of the East Anglian dialect word bunny ‘lump, swelling’, representing a 15th-century form bony, glossed in a contemporary English-Latin dictionary as ‘great knob’. This was apparently borrowed from Old French hugne ‘bump on the head’. [bunion etymology, bunion origin, 英语词源]
1718, apparently from East Anglian dialectic bunny "lump, swelling" (16c.), which is probably from Middle French buigne "bump on the head, swelling from a blow" (see bun).