trigger

Etymology

Originally tricker, from Dutch trekker (“pull”, noun, as in drawer-pull, bell-pull), from Dutch trekken (“to drag, draw, pull”).

noun

1. (firearms) A finger-operated lever used to fire a gun.
   Just pull the trigger.
2. A similar device used to activate any mechanism.
3. An event that initiates others, or incites a response.
   Sleeping in an unfamiliar room can be a trigger for sleepwalking.
4. A concept or image that upsets somebody by sparking a negative emotional response.
   I can't watch that violent film. Blood is one of my triggers.
5. (psychology) An event, experience or other stimulus that initiates a traumatic memory or a strong reaction in a person.
6. (music) An electronic transducer allowing a drum, cymbal, etc. to control an electronic drum unit or similar device.
7. (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.
8. (electronics) A pulse in an electronic circuit that initiates some component.
9. (databases) An SQL procedure that may be initiated when a record is inserted, updated or deleted; typically used to maintain referential integrity.
10. (online gaming) A text string that, when received by a player, will cause the player to execute a certain command.
11. (archaic) A catch to hold the wheel of a carriage on a declivity.

verb

1. (transitive) To fire a weapon.
   A U235 bomb would therefore need to incorporate a gun weighing ten tons. Then there was the question of initiating or triggering the bomb. 2011, Jim Baggott, The First War of Physics, Pegasus Books
2. (transitive) To initiate something.
   The controversial article triggered a deluge of angry letters from readers.
   The accident followed torrential early morning rain that triggered widespread flooding across Scotland's tracks, including south of Carmont. August 26 2020, Philip Haigh, “Network News: Three die in ScotRail landslip derailment at Carmont”, in Rail, page 6
3. (transitive, figurative) To spark a response, especially a negative emotional response, in (someone).
   This story contains a rape scene and may be triggering for rape victims.
   People get triggered simply by seeing a Trump. 2019, Donald Trump Jr., Triggered, Center Street
   “I think I trigger a lot of their primal rage,” Mr. Greenwald said, referring to Brazilians who support the president. “They view me as someone who deserves to be punished.” (transitive, figurative, by extension of above, Internet slang) To intentionally offend someone, especially by expressing radical or edgy opinions. I encountered a forum user who didn't agree with me, so I wrote some comments with my political slogans to trigger that clueless kiddo. 2020-01-25, Ernesto Londoño, Letícia Casado, “Glenn Greenwald in Bolsonaro’s Brazil”, in The New York Times, →ISSN
4. (intransitive, especially electronics) To activate; to become active.
   Sodium nitrite (750 ppm) was added after the alarm triggered at three hours, and corrosion did not occur for over eight hours. 1997, Mill Operators' Conference, page 182