three-phase

[ three-feyz ]

adjective

, Electricity.

1. of or relating to a circuit, system, or device that is energized by three electromotive forces that differ in phase by one third of a cycle or 120°.
2. having three phases.

three-phase

adjective

1. (of an electrical system, circuit, or device) having, generating, or using three alternating voltages of the same frequency, displaced in phase by 120°

Word History and Origins

Origin of three-phase¹

First recorded in 1890–95