名詞 bunion:

1. a painful swelling of the bursa of the first joint of the big toe

bun.ion

n.（名詞）
A painful, inflamed swelling of the bursa at the first joint of the big toe, characterized by enlargement of the joint and lateral displacement of the toe.
拇趾囊腫脹：大拇趾第一關節(jié)處疼痛的，發(fā)炎的囊腫，特征是關節(jié)腫大，然后拇趾移位

來源：
Probably alteration of obsolete bunny [swelling]
可能為 廢語 bunny的變化 [腫脹]
from Middle English bony
源自 中古英語 bony
perhaps from Old French bugne * see bun
可能源自 古法語 bugne *參見 bun