a small projecting tongue in a firearm that, when pressed by the finger, actuates the mechanism that discharges the weapon.

a device, as a lever, the pulling or pressing of which releases a detent or spring.

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

Slang . triggerman.

to initiate or precipitate (a chain of events, scientific reaction, psychological process, etc.)

Their small protest triggered a mass demonstration.

to fire or explode (a gun, missile, etc.) by pulling a trigger or releasing a triggering device

He accidentally triggered his rifle.

to release a trigger.

to become active; activate. ?

quick on the trigger

Informal . quick to act or respond; impetuous; alert.

verb

block , check , halt , stop

verb

activate , bring about , cause , elicit , generate , give rise to , produce , prompt , provoke , set in motion , set off , spark , start , bring , bring on , effect , effectuate , induce , ingenerate , lead to , make , occasion , result in , secure , stir , touch off , egg on , excite , foment , galvanize , goad , impel , incite , inflame , inspire , instigate , motivate , move , pique , prick , prod , propel , spur , stimulate , work up , initiate , lever , release

noun

goad , incitation , incitement , instigation , provocation