late 15c., with -y(2) + ware, from Old English wær "prudent, aware, alert, wary," from Proto-Germanic *waraz (cognates: Old Norse varr "attentive," Gothic wars "cautious," Old Saxon giwar, Middle Dutch gheware, Old High German giwar, German gewahr "aware"), from PIE root *wer- (4) "to perceive, watch out for" (see ward, n.). Related: Warily; wariness.