hair-trig·​ger | \ ˈher-ˌtri-gər How to pronounce hair-trigger (audio) \

Definition of hair-trigger

 (Entry 1 of 2)

1 : immediately responsive to the slightest stimulus a hair-trigger temper
2 : delicately adjusted or easily disrupted

hair trigger


Definition of hair trigger (Entry 2 of 2)

: a gun trigger so adjusted as to permit the firearm to be fired by a very slight pressure

Examples of hair-trigger in a Sentence

Recent Examples on the Web: Noun The demon core, destined for use in a weapon of mass destruction, was designed to have a hair trigger. Julian G. West, The Atlantic, "The Atomic-Bomb Core That Escaped World War II," 2 Apr. 2018 The accelerator's hair trigger delivered more responsiveness for quicker pep off the line, and the ride felt much firmer — even choppy at times. Jennifer Geiger, USA TODAY, "Review: Audi's SQ5 blazes new SUV trails," 23 Feb. 2018 Since Lynx, my 4-year-old daughter, dragged a bundle of harnesses into the yard, our sled dogs — which have a hair trigger that goes off at the first sight of any mushing gear — had been in a literal frenzy. Joseph Robertia, Anchorage Daily News, "Frenzied sled dogs, an eager 4-year-old, and an Alaska rite of passage," 1 Feb. 2018 Dynamics were modulated as if on a hair trigger, whether thanks to the preparation of the choir’s director, Joe Miller, or to the ministrations of this year’s early-music import, the British maestro Andrew Manze. James R. Oestreich, New York Times, "Review: Philharmonic Replies to $50 Million With ‘Hallelujah’," 13 Dec. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'hair-trigger.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of hair-trigger


1834, in the meaning defined at sense 1


1802, in the meaning defined above

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Time Traveler for hair-trigger

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The first known use of hair-trigger was in 1802

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Statistics for hair-trigger

Cite this Entry

“Hair-trigger.” The Dictionary, Merriam-Webster Inc., Accessed 19 January 2020.

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How to pronounce hair trigger (audio)

English Language Learners Definition of hair-trigger

 (Entry 1 of 2)

: becoming angry very easily

hair trigger


English Language Learners Definition of hair trigger (Entry 2 of 2)

: a trigger on a gun that needs very little pressure to cause the gun to shoot

Comments on hair-trigger

What made you want to look up hair-trigger? Please tell us where you read or heard it (including the quote, if possible).


to insert between existing elements

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