(Electricity) Of a current that reverses direction at regular intervals.

Množina: alternating currents

Electric current that reverses its direction of flow (polarity) periodically according to a frequency measured in hertz, or cycles per second. Acronym: AC. Compare direct current.
An electric current that reverses direction sinusoidally; SYN. AC.
(AC) Electric current that flows for an interval of time in one direction and then in the opposite direction, that is, a current that flows in alternately reversed directions through or around a circuit. Electric energy is usually generated as alternating current in a power station, and alternating currents may be used for both power and lighting.
The advantage of alternating current over direct current (DC), as from a battery, is that its voltage can be raised or lowered economically by a transformer: high voltage for generation and transmission, and low voltage for safe utilization. Railroads, factories, and domestic appliances, for example, use alternating current.

Množina: alternating current generators

Intermittently, remittently