withers (n.)youdaoicibaDictYouDict[withers 词源字典]
1570s, probably from a dialectal survival of Old English wiðer "against, contrary, opposite" (see with) + plural suffix. Usually said to be so called because the withers are the parts of the animal that oppose the load. Compare German Widerrist "withers," from wider "against" + Rist "wrist."[withers etymology, withers origin, 英语词源]