1580, from Old English dialectical wiðer (“against”) + -s; see with. So-named because the part of the horse that pushes against a load. Compare German Widerrist (“withers”), from wider (“against”) + Rist (“wrist”).
withers (plural only)
- (veterinary medicine) The part of the back of a draft animal or horse that is the highest, between the shoulder blades.
Usage notes 
Although this noun refers to one object, there is no corresponding singular form *wither for this word, the singular form being obsolete.
Coordinate terms 
Derived terms 
- Third-person singular simple present indicative form of wither.