trig·​ger | \ˈtri-gər \

Definition of trigger 

(Entry 1 of 2)

1a : a piece (such as a lever) connected with a catch or detent as a means of releasing it especially : the part of the action moved by the finger to fire a gun

b : a similar movable part by which a mechanism is actuated trigger of a spray gun

2 : something that acts like a mechanical trigger in initiating a process or reaction


triggered; triggering\ˈtri-​g(ə-​)riŋ \

Definition of trigger (Entry 2 of 2)

transitive verb

1a : to release or activate by means of a trigger especially : to fire by pulling a mechanical trigger trigger a rifle

b : to cause the explosion of trigger a missile with a proximity fuse

2 : to initiate, actuate, or set off by a trigger an indiscreet remark that triggered a fight a stimulus that triggered a reflex

3 : to cause an intense and usually negative emotional reaction in (someone) Water had a way of triggering my brother and making ordinary, everyday weather take a frightening turn for the worse.— Ingrid Law

intransitive verb

: to release a mechanical trigger

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Other Words from trigger


triggered \ˈtri-​gərd \ adjective

Synonyms & Antonyms for trigger

Synonyms: Verb

activate, actuate, crank (up), drive, move, run, set off, spark, start, touch off, turn on

Antonyms: Verb

cut, cut out, deactivate, kill, shut off, turn off

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Examples of trigger in a Sentence


Smoke triggered the fire alarm. The timer was set to trigger the bomb in exactly one hour. His remarks triggered a public outcry. Certain foods trigger his headaches. The power outage was triggered by heavy rains.
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Recent Examples on the Web: Noun

But there can also be acute triggers for heart attacks, like exertion, strong emotions, natural disasters, and, studies show, watching a tense soccer game. Rachel Becker, The Verge, "How watching the World Cup final might affect your health," 14 July 2018 Officials, business owners and real estate developers see the terminal as a trigger for economic development. Rachel Swan,, "Soon-to-open Richmond ferry terminal could revive shoreline, usher in gentrification," 5 July 2018 Avoid trigger words Lead by example, Smolar says, and don’t talk unnecessarily about food, calories, or your own weight. Sarah Klein,, "9 Ways to Help a Friend With an Eating Disorder," 28 Feb. 2018 Anti-Semitic, nationalistic, isolationist, racist, fascist—Jones is a walking bingo card of liberal trigger words—and cartoonishly so. Ian Graber-stiehl, The Root, "Chi-Town, Check Your Damn Blind Spots; I Have a Lifelong Nazi as GOP Congressional Nominee in My Backyard," 9 Feb. 2018 Chella: Looking back, analyzing my triggers was extremely helpful. Chella Man, Teen Vogue, "What It’s Like to Be Trans and Live With Gender Dysphoria," 21 Sep. 2018 Johnson is the prosecutor who helped a couple of trigger-happy Glynn County cops avoid prosecution in the sickening 2010 shooting death of Caroline Small, an unarmed mother trapped in her car after a slow-speed chase. Bill Torpy, ajc, "Torpy at Large: Something stinks in Brunswick, and it ain’t paper mills," 11 July 2018 Today’s version of the AR-15 rifle is marketed to civilians solely as a semiautomatic weapon, which means one round is fired with each pull of the trigger. John Tedesco, San Antonio Express-News, "‘Joe Pags Show’ in the national spotlight after Ted Nugent interview," 6 Apr. 2018 Scents can be a powerful trigger for emotion and memory, stimulating the olfactory nerve and sending signals directly to the brain. Karen Campbell,, "Trouble sleeping? Let your senses be your guide," 12 July 2018

Recent Examples on the Web: Verb

The ozone, sulfur and nitrogen compounds, and fine particles that comprise this pollution can inflame airways, which in turn can trigger breathing issues and heart problems, and exacerbate illnesses. Umair Irfan, Vox, "How improving air quality could add years to people’s lives around the world.," 21 Nov. 2018 When someone has gone through a traumatic event, they can also be triggered and re-traumatized by current events in the news, such as the Kavanaugh hearings or Pittsburgh synagogue massacre. Rachel Anspach, Teen Vogue, "Trump's Policies Are Increasing Teen Stress and Eroding Mental Health," 12 Nov. 2018 Some people with type 2 diabetes take medications to increase their insulin sensitivity, which can trigger low blood sugar, Dr. Lee says. Carolyn L. Todd, SELF, "Why a ‘Sugar Hangover’ Can Feel as Terrible as the Real Thing," 27 Oct. 2018 After one parent made a complaint that a child didn’t make the cut after last month’s tryouts, Hanover Park High School officials rolled out the new policy — which triggered backlash of its own. Paulina Dedaj, Fox News, "'Inclusive' cheerleading policy rolled out at high school after parent complained child missed the cut," 2 Oct. 2018 This order then incites swifter cell turnover and more robust growth-factor output, which then triggers more collagen creation down below the surface for glowier, plumper, prettier skin. Jolene Edgar, Allure, "The Truth About Growth Factors in Skin Care and Why They're Controversial," 2 Aug. 2018 The authors chose fat cells, which typically don't trigger an immune response when transplanted to a new animal. John Timmer, Ars Technica, "Drugs that kill off old cells may limit a body’s aging," 10 July 2018 Where was the consideration that such an image could be considered triggering, especially from a network that ostensibly knows better by now? Taylor Crumpton, Teen Vogue, "How "Chilling Adventures of Sabrina" Failed Prudence Night," 1 Nov. 2018 The attacker then triggers the overflow by sending a standard advertising packet with one subtle change—a specific bit in the header is turned on instead of off. Dan Goodin, Ars Technica, "Bluetooth bugs bite millions of Wi-Fi APs from Cisco, Meraki, and Aruba," 1 Nov. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'trigger.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of trigger


1621, in the meaning defined at sense 1a


1916, in the meaning defined at transitive sense 1a

History and Etymology for trigger


alteration of earlier tricker, from Dutch trekker, from Middle Dutch trecker one that pulls, from trecken to pull — more at trek

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Statistics for trigger

Last Updated

9 Dec 2018

Look-up Popularity

Time Traveler for trigger

The first known use of trigger was in 1621

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More Definitions for trigger



English Language Learners Definition of trigger

 (Entry 1 of 2)

: a lever on a gun that you pull to fire the gun

: something that causes something else to happen



English Language Learners Definition of trigger (Entry 2 of 2)

: to cause (something, such as an alarm) to start functioning

: to cause (a bomb) to explode

: to cause (something) to start or happen


trig·​ger | \ˈtri-gər \

Kids Definition of trigger

: the part of the lock of a gun that is pressed to release the hammer so that it will fire

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Comments on trigger

What made you want to look up trigger? Please tell us where you read or heard it (including the quote, if possible).


the figure or shape of a crescent moon

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