trigger

nouns

lever that activates the firing mechanism of a gun

gun trigger, trigger

a device that activates or releases or causes something to happen

trigger

is a type of (narrower)

an instrumentality invented for a particular purpose

"the device is small enough to wear on your wrist"; "a device intended to conserve water"

an act that sets in motion some course of events

induction, initiation, trigger

put in motion or move to act

"trigger a reaction"; "actuate the circuits"

activate, actuate, set off, spark, spark off, touch off, trigger, trigger off, trip

release or pull the trigger on

"Trigger a gun"

trigger

entails

cause to go off

"fire a gun"; "fire a bullet"