Wattless \Watt"less\, a. (Elec.)
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.
[Webster 1913 Suppl.]