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 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

Synonyms

Verb

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

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

According to behavioral researchers, acts of generosity trigger positive emotions not only in recipients, but also in those who perform them. —Barbara A. Perry, Newsweek, 28 Jan. 2025

Rosacea triggers are factors that lead to a flare-up or worsen symptoms. —Carrie Madormo, Rn, Mph, Verywell Health, 27 Jan. 2025

Verb

Sudden immersion in such frigid water, known as cold shock, can trigger immediate physiological responses such as uncontrolled gasping, rapid breathing or hyperventilation, according to the National Weather Service. —Rebekah Riess, CNN, 30 Jan. 2025

The loss triggered cascade of losses for other tech companies and consequently a major 3% downdraft in the Nasdaq index. —Michael Hiltzik, Los Angeles Times, 30 Jan. 2025

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

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