Word Study
wattless
CIDE DICTIONARY
wattless, a.
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.]
For further exploring for "wattless" in Webster Dictionary Online