adjective Electricity.

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°.
having three phases.

Origin of three-phase

First recorded in 1890–95 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for three-phase

Historical Examples of three-phase

  • The result produced by three such coils is called a three-phase current.


    Willis Eugene Tower

  • They are three-phase machines, delivering twenty-five cycle alternating currents at an effective potential of 11,000 volts.

  • The round dial instrument shown at the bottom of each row of instruments is a three-phase recording wattmeter.

  • It will be seen, therefore, that by doubling the three-phase system the pulsations are already very greatly reduced.

  • The rail mill is operated by three-phase induction motors of from 2000 to 6000 horse-power capacity.

British Dictionary definitions for three-phase



(of an electrical system, circuit, or device) having, generating, or using three alternating voltages of the same frequency, displaced in phase by 120°
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012