c.1300, from O.Fr. harneis, perhaps from O.N. *hernest "provisions for an army," from herr "army" + nest "provisions." Ger. Harnisch "harness, armor" is the O.Fr. word, borrowed into M.H.G. The verb meaning "to put a harness on a draught animal" is from c.1300; figurative sense is from 1698.