trigger

American  

[trig-er] / ˈtrɪg ər /

noun

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.

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

4. 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.

5. Slang. triggerman.

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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.

3. 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

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

trigger British  

/ ˈtrɪɡə /

noun

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

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

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verb

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

trigger More Idioms  

More idioms and phrases containing trigger

• quick on the draw (trigger)

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Other Word Forms

• triggered adjective
• triggerless adjective

Etymology

Origin of trigger

First recorded in 1615–25; earlier tricker, from Dutch trekker, equivalent to trekk(en) “to pull” + -er -er ¹

Example Sentences

Earlier this month, the launch of new artificial-intelligence tools by Anthropic triggered a broad industry selloff, reflecting market concerns about potential AI-driven disruption.

From The Wall Street Journal

The by-election was triggered by the resignation of now former Labour MP Andrew Gwynne on 22 January on the grounds of ill health.

From BBC

Around 880 tonnes of hazardous material remain inside the power station, the site of one of the world's worst nuclear accidents after a tsunami was triggered by a 9.0-magnitude earthquake.

From Barron's

Overlapping plots and jurisdictions trigger intractable land disputes.

From Barron's

Operating losses increased, triggering a steep selloff in the stock and prompting management to withdraw its financial guidance for all of fiscal 2026.

From Barron's

Related Words

• bring about
• cause
• generate
• produce
• prompt
• provoke
• set off
• spark
• start