a. The lever pressed by the finger to discharge a firearm.
b. A similar device used to release or activate a mechanism.
2. Something that precipitates a particular event or situation.
3. Something that induces intense emotional distress, especially by evoking memories of past trauma.
4. Electronics A pulse or circuit that initiates the action of another component.
tr.v. trig·gered, trig·ger·ing, trig·gers
1. To set off; initiate: remarks that triggered bitter debates; allergens that trigger asthma attacks.
a. To induce (a powerful emotional reaction): a situation that triggered a panic attack in the patient.
b. To induce a powerful emotional reaction in, especially by evoking memories of past trauma: avoided watching films that might trigger him.
3. To fire or explode (a weapon or an explosive charge).
[Dutch trekker, from Middle Dutch trecker, from trecken, to pull.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.