Meaning

noun the highest part of the back at the base of the neck of various animals especially draft animals

verb wither, as with a loss of moisture

verb lose freshness, vigor, or vitality

originFrom dialectal English wither (“against”) (compare wither-) + -s; see with. So-named because it is the part of the horse that pushes against a load. Compare German Widerrist (“withers”), from wider (“against”) + Rist (“wrist”).

Etymology from Wiktionary, CC BY-SA 3.0