Definition of trigger hair in English:

Share this entry

trigger hair


1A hairlike structure that triggers a rapid movement when touched, in particular.
Example sentences
  • They are being observed by Major König who spies on them from an adjoining building and is waiting for the slightest glimpse of a human target in the trigger hairs of his sights.
  • Electron micrographs of the active zone of the trigger hair reveal three regions in which the cells differ in size, shape, and cytoplasmic content.
  • As a result, only one internal trigger hair stimulus is required to effect rapid trap closure.
1.1 Zoology (In a coelenterate) a filament at the mouth of a nematocyst, triggering the emission of the stinging hair.
Example sentences
  • At the narrow outer edge of the cnidocyte is a short trigger hair.
  • When the trigger hair on the outside of a nematocyte is touched, a coiled thread tube inside the enclosed nematocyst is released.
1.2 Botany A bristle on the leaf of a Venus flytrap, triggering the closure of the leaf around an insect.
Example sentences
  • The first phase of the leaf closure begins when a trigger hair is disturbed.
  • The flytrap features a set of inch-long, heart-shaped capture leaves, each fringed with trigger hairs and bisected by a deep fold.
  • Darwin's investigation into the biology of the Venus flytrap involved testing the sensitivity of trigger hairs.

For editors and proofreaders

Syllabification: trig·ger hair

Share this entry

What do you find interesting about this word or phrase?

Comments that don't adhere to our Community Guidelines may be moderated or removed.