a trigger of a firearm that responds to very slight pressure
informal
any mechanism, reaction, etc, set in operation by slight provocation
( as modifier )
a hair-trigger temper
First recorded in 1815–25
First recorded in 1885–90
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Years of mismanagement and ill-fated transfers have left Spurs with a jumbled squad and a hair trigger for firing coaches.
From The Wall Street Journal • Mar. 14, 2026
Investors appear to have been on hair trigger.
From Barron's • Dec. 22, 2025
He’s in a stage in his career when he’s on a hair trigger to tuck the ball and run.
From Los Angeles Times • Oct. 5, 2021
The $149.99 Xbox Elite Controller includes three thumbsticks of varying heights, two d-pads, four removable paddles, hair trigger locks, a USB cable and a carrying case.
From The Verge • Oct. 22, 2015
His sense of right and wrong had been mounted on a hair trigger.
From "Friday Night Lights: A Town, A Team, And A Dream" by H.G. Bissinger
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
