1540s, probably from Old English wice "Applied generally or vaguely to various trees having pliant branches" [OED], from wican "to bend," related to weak (see vicarious) + hæsel, used for any bush of the pine family (see hazel, n.). The North American bush, from which a soothing lotion is made, was so called from 1670s. This is the source of the verb witch in dowsing.