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

Keep scrolling for more

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

Visit the Thesaurus for More 

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.
See More

Recent Examples on the Web: Noun

Before pulling the trigger on a big online home-furnishing purchase: measure. Allison Duncan, WSJ, "The Expert’s Guide to Scoring Décor Deals Online," 14 Feb. 2019 While confirmation bias is usually invisible to us in the moment, its physiological triggers are more detectable. Liv Boeree, Vox, "How an 18th-century priest gave us the tools to make better decisions," 30 Nov. 2018 That means customers will have to weigh his promises about deliveries before the end of the year against the company’s actual track record before pulling the trigger on a new Model 3. Andrew J. Hawkins, The Verge, "Tesla promises all cars ordered by October 15th will qualify for $7,500 tax break," 12 Oct. 2018 Five years ago, 25-year-old radical libertarian Cody Wilson stood on a remote central Texas gun range and pulled the trigger on the world’s first fully 3-D-printed gun. Adam Fisher, WIRED, "A Landmark Legal Shift Opens Pandora’s Box for DIY Guns," 10 July 2018 These folks may even have their financing lined up but can’t pull the trigger on a purchase. Kenya Burrell-vanwormer, Houston Chronicle, "Realtor View: Buyer’s personality can affect sale," 1 July 2018 But the adjacent, high-tech AP60 smelter is seen as the real future for production here, especially if Rio pulls the trigger on an expansion there and on a fifth smelter, Alma, in nearby Lac-Saint-Jean. Danielle Bochove,, "Trump’s Trade War Looms Over a Canadian Town Built to Supply America," 28 June 2018 Faced with a similar situation last season with star forward Paul George, Indiana waited until July 6 to pull the trigger on a deal with Oklahoma City. Jeff Mcdonald, San Antonio Express-News, "With Leonard in limbo, Spurs may face franchise-shaping draft night," 20 June 2018 Discussions about ending the sometimes unwieldy morning meeting had occurred before the Sadler leak, the senior official said, but senior staffers decided to pull the trigger on a number of internal changes in the wake of the McCain controversy. Sarah Westwood, CNN, "White House cancels daily communications meeting after McCain joke leaks," 17 May 2018

Recent Examples on the Web: Verb

Stress triggers the release of the hormone cortisol, which encourages your body to store more fat, particularly around your belly. Karyn Repinski, Woman's Day, "New Research Links Belly Fat to an Increased Risk of Heart Attacks in Women," 23 Jan. 2019 Oil has been leaking from the site since waves whipped up by Hurricane Ivan triggered an underwater mudslide that wrecked Taylor Energy’s platform. Michael Kunzelman, The Seattle Times, "Company can be ordered to drill to end 14-year-old oil leak," 21 Nov. 2018 As the storm continues to track toward western North Carolina and upstate South Carolina, heavy rains in the mountains could trigger mudslides due to the region’s topography, Cline added. Kaitlyn Schallhorn, Fox News, "Hurricane Florence could bring life-threatening floods, conditions to areas away from coastline as well," 13 Sep. 2018 If so, that triggers the automatic sanctions to freeze the assets of the specific culprit(s). Alex Ward, Vox, "Trump just signed a measure to punish foreigners for interfering in US elections," 12 Sep. 2018 The completion of the initial draft environmental report triggers a 45-day public comment period, a necessary step before the San Diego International Airport can proceed with actual construction, expected to start in 2020. Lori Weisberg,, "Airport releases environmental analysis of $3B plan to redevelop terminals," 10 July 2018 However, forecasters warned that may not occur in time to spare the Dominican Republic and Haiti, where storms often trigger dangerous mudslides and flash flooding. Jenny Staletovich, miamiherald, "Beryl bound for Caribbean islands, possibly as a 90-mph hurricane," 6 July 2018 The work also triggers the guilty memory of the murder of Nikki Bolio, a young woman Richter had interviewed while doing research for an investigative journalist’s exposé on New England drug dealing. Paula L. Woods,, "The L.A. art scene is the setting for the mystery 'Still Lives' by Maria Hummel," 29 June 2018 That instantly triggers dead circuits for anywhere from hundreds to thousands of customers, although usually for just a few hours, managers said. Bill Laitner, Detroit Free Press, "History of power outages riles metro Detroiters, DTE promises fixes," 28 June 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.

See More

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

Keep scrolling for more

Learn More about trigger

Statistics for trigger

Last Updated

18 Feb 2019

Look-up Popularity

Time Traveler for trigger

The first known use of trigger was in 1621

See more words from the same year

Keep scrolling for more

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

Keep scrolling for more

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).


very full or close together

Get Word of the Day daily email!

Test Your Vocabulary

What did you just call me?! A Quiz

  • rows-of-various-emoji
  • If a member of the audience describes your speech as bombastic, does that person mean it is:
Name That Thing

Test your visual vocabulary with our 10-question challenge!

Bee Cubed

Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!