[ trig-er ]
See synonyms for: triggertriggeredtriggeringtriggers on

  1. a small projecting tongue in a firearm that, when pressed by the finger, actuates the mechanism that discharges the weapon.

  2. a device, as a lever, the pulling or pressing of which releases a catch or spring.

  1. anything, as an act or event, that serves as a stimulus and initiates or precipitates a reaction or series of reactions.

  2. something that evokes the memory of a traumatic experience, setting off an intense negative emotional reaction: This issue of the magazine contains accounts of sexual assault, and may be a trigger for some people.

  3. Slang. triggerman.

verb (used with object)
  1. to initiate or precipitate (a chain of events, scientific reaction, psychological process, etc.): Their small protest triggered a mass demonstration.

  2. to fire or explode (a gun, missile, etc.) by pulling a trigger or releasing a triggering device: He accidentally triggered his rifle.

  1. to set off a negative emotional reaction in (someone), as by evoking the memory of a traumatic experience, repeatedly raising a sensitive issue, etc.: I missed seeing my mom in the ICU before she died, and imagining her there triggers me every time I see ICU footage on TV.

verb (used without object)
  1. to release a trigger.

  2. to become active; activate.

Idioms about trigger

  1. quick on the trigger, Informal. quick to act or respond; impetuous; alert.

Origin of trigger

First recorded in 1615–25; earlier tricker, from Dutch trekker, equivalent to trekk(en) “to pull” + -er -er1

Words Nearby trigger Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use trigger in a sentence

British Dictionary definitions for trigger


/ (ˈtrɪɡə) /

  1. a small projecting lever that activates the firing mechanism of a firearm

  2. machinery a device that releases a spring-loaded mechanism or a similar arrangement

  1. any event that sets a course of action in motion

  1. (usually foll by off) to give rise (to); set off

  2. to fire or set in motion by or as by pulling a trigger

Origin of trigger

C17 tricker, from Dutch trekker, from trekken to pull; see trek

Derived forms of trigger

  • triggered, adjective
  • triggerless, adjective

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

Other Idioms and Phrases with trigger


In addition to the idiom beginning with trigger

  • trigger happy

also see:

  • quick on the draw (trigger)

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.