1. Physical or mental weariness resulting from effort or activity.
2. Something, such as tiring effort or activity, that causes tiredness or weariness: the fatigue of a long hike.
3. Physiology The decreased capacity or complete inability of an organism, organ, or part to function normally because of excessive stimulation or prolonged exertion.
4. The weakening or failure of a material, such as metal or wood, resulting from prolonged stress.
a. Manual or menial labor, such as barracks cleaning, assigned to soldiers.
b. fatigues Clothing worn by military personnel for labor or for field duty.
v. fa·tigued, fa·tigu·ing, fa·tigues
1. To tire out; exhaust.
2. To create fatigue in (a metal or other material).
To be or become tired. See Synonyms at tire1.
[French, from Old French, from fatiguer, to fatigue, from Latin fatīgāre.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 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.