wattless

In electricity, consuming no power. A wattless alternating current is a current differing in phase by 90 degrees from the electromotive force; a wattless electromotive force is an electromotive force differing in phase by 90 degrees from the current. A better term is reactive.

Without any power (cf. watt); — said of an alternating current or component of current when it differs in phase by ninety degrees from the electromotive force which produces it, or of an electromotive force or component thereof when the current it produces differs from it in phase by 90 degrees.