n. 1. a. The lever pressed by the finger to discharge a firearm.
b. A similar device used to release or activate a mechanism.
2. Something that precipitates a particular event or situation.
3. Something that induces intense emotional distress, especially by evoking memories of past trauma.
4. Electronics A pulse or circuit that initiates the action of another component.
tr.v. trig·gered, trig·ger·ing, trig·gers 1. To set off; initiate: remarks that triggered bitter debates; allergens that trigger asthma attacks.
2. a. To induce (a powerful emotional reaction): a situation that triggered a panic attack in the patient.
b. To induce a powerful emotional reaction in, especially by evoking memories of past trauma: avoided watching films that might trigger him.
3. To fire or explode (a weapon or an explosive charge).