hair-trigger

plural hair-triggers · alternative hair trigger

1. A trigger that will set off a firearm when even a very small pressure is applied.

   Is your laugh hung on a hair-trigger?—that is, is it critical, or can you get it off easy?

   1870–1871 (date written), Mark Twain [pseudonym; Samuel Langhorne Clemens], “”, in Roughing It, Hartford, Conn.: American Publishing Company [et al.], published 1872, →OCLC, page 560

   1 more example

   […]the hunter brings the sight of his rifle to bear; lightly and delicately his finger presses upon the hair-trigger.

   1847, Francis Parkman, The Oregon Trail

alternative hair trigger

1. not comparableUnstable; in a situation that could be worsened by the slightest mistake.
2. not comparableEasily angered; having a short temper.

   "Gus," the latter began, "am I right in assuming that you possess a reasonable amount of influence with that hair-trigger partner of yours, Live Wire Luiz?"

   1922, Peter B. Kyne, Cappy Rick Retires, page 339

   1 more example

   [I]n the 575 days since [Oscar] Pistorius shot dead his girlfriend Reeva Steenkamp, there has been an unseemly scramble to construct revisionist histories, to identify evidence beneath that placid exterior of a pugnacious, hair-trigger personality.

   2014 October 21, Oliver Brown, “Oscar Pistorius jailed for five years – sport afforded no protection against his tragic fallibilities: Bladerunner's punishment for killing Reeva Steenkamp is but a frippery when set against the burden that her bereft parents, June and Barry, must carry [print version: No room for sentimentality in this tragedy, 13 September 2014, p. S22]”, in The Daily Telegraph (Sport)

   Synonyms: hair-triggered