trigger

IPA: trˈɪgɝ

(firearms) A finger-operated lever used to fire a gun.
A similar device used to activate any mechanism.
An event that initiates others, or incites a response.
A concept or image that upsets somebody by sparking a negative emotional response.
(psychology) An event, experience or other stimulus that initiates a traumatic memory or a strong reaction in a person.
(music) An electronic transducer allowing a drum, cymbal, etc. to control an electronic drum unit or similar device.
(music) A device that manually lengthens (or sometimes shortens) the slide or tubing of a brass instrument, allowing the pitch range to be altered while playing.
(electronics) A pulse in an electronic circuit that initiates some component.
(databases) An SQL procedure that may be initiated when a record is inserted, updated or deleted; typically used to maintain referential integrity.
(online gaming) A text string that, when received by a player, will cause the player to execute a certain command.
(archaic) A catch to hold the wheel of a carriage on a declivity.

(transitive) To fire a weapon.
(transitive) To initiate something.
(transitive, figurative) To spark a response, especially a negative emotional response, in (someone).
(intransitive, especially electronics) To activate; to become active.

Examples of "trigger" in Sentences

Slickest bolt on the market and the trigger is also quite good.
True, the trigger is as good as any I've ever touched off on any hunting rifle.
The trigger is NOT a compromise, as another comment asserted: the trigger is a trick to sneak the public option in at a later date. katiec
For those who might be offended by the analogy, remember: the word trigger is best known as the term for the mechanism that fires a gun, or for the device that sets off a bomb.