Alternating current
WordNet
noun
(1) An electric current that reverses direction sinusoidally
"In the US most household current is AC at 60 cycles per second"
WiktionaryText
Noun
- an electric current in which the direction of flow of the electrons reverses periodically having an average of zero, with positive and negative values (with a frequency of 50 Hz in Europe, 60 Hz in the US, 400 Hz for airport lighting, and some others); especially such a current produced by a rotating generator or alternator.