Noun
triac (plural triacs)
(electronics) A three-terminal electronic component that conducts current in either direction when triggered; a bidirectional triode thyristor.
TRIAC (plural TRIACs)
Alternative form of triac
These modules switch the power using a TRIAC solid state switch and are also capable of dimming the lamp load. Source: Internet
See Friedel and Israel Edison's Electric Light pages 29–31 Since incandescent lamps are resistive loads, simple phase-control TRIAC dimmers can be used to control brightness. Source: Internet