trigger

1 of 2

noun

trig·​ger ˈtri-gər 

1

a

: 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

trigger

2 of 2

verb

triggered; triggering ˈtri-g(ə-)riŋ 

transitive verb

1

a

: 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

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

Synonyms of trigger

Verb

• activate
• spark
• drive

Examples of trigger in a Sentence

Verb

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.

Recent Examples on the Web

Noun

That kind of improvement could help avoid a worst-case scenario the Fed has been desperate to avoid, one where expectations for high inflation trigger a vicious cycle of behavior that only worsens inflation. —Stan Choe, Los Angeles Times, 23 Jan. 2026

The bill applies to both public and private employers and adopts the same conditional-offer trigger used by New York City’s Fair Chance Act. —Alonzo Martinez, Forbes.com, 23 Jan. 2026

Verb

The managers also were aware of Mace's recent hospitalizations, according to the attorneys, which should have triggered concern and action. —Dan Morse The Washington Post, Arkansas Online, 23 Jan. 2026

It was likely triggered by the intense heat from micrometeorite impacts, volcanic activity, and solar wind. —Mrigakshi Dixit, Interesting Engineering, 22 Jan. 2026

Word History

Etymology

Noun

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

First Known Use

Noun

1621, in the meaning defined at sense 1a

Verb

1902, in the meaning defined at transitive sense 1a

Phrases Containing trigger

• hair trigger
• pull the trigger
• quick on the trigger
• trigger ban
• trigger-happy
• trigger law
• trigger point

Rhymes for trigger

• bigger
• digger
• jigger
• rigger
• rigor
• vigor
• gravedigger
• obligor
• outrigger

Kids Definition

trigger

1 of 2 noun

trig·​ger ˈtrig-ər 

1

: a movable lever that activates a device when it is squeezed

especially : the part of the lock of a firearm that releases the hammer and so fires the gun

2

: something that causes something else to happen

trigger adjective

triggered

-ərd 

adjective

trigger

2 of 2 verb

triggered; triggering -(ə-)riŋ 

1

: to fire by pulling a trigger

2

: to begin, stir up, or set in motion as if by pulling a trigger

the remark that triggered the laughter