fatigueyoudaoicibaDictYouDict[fatigue 词源字典]
fatigue: [17] In English a relatively formal term, fatigue goes back ultimately to a Latin expression roughly equivalent to the English notion of having ‘had it up to here’. It was borrowed from French fatiguer, a descendant of Latin fatigāre ‘tire’. This appears to have been related to the adverb affatim ‘sufficiently’, suggesting that underlying fatigāre was the idea of having ‘had enough’. The derivative indefatigable ‘tireless’ [16] comes from Latin indēfatigābilis.
[fatigue etymology, fatigue origin, 英语词源]
fatigue (n.)youdaoicibaDictYouDict
1660s, "that which causes weariness," from French fatigue "weariness," from fatiguer "to tire" (15c.), from Latin fatigare "to weary, to tire out," originally "to cause to break down," from pre-Latin adjective *fati-agos "driving to the point of breakdown," with first half from Old Latin *fatis, which is of unknown origin but apparently related to affatim (adv.) "sufficiently" and to fatisci "crack, split." The second half is the root of agere "to drive" (see act (n.)).

Especially "the labors of military persons" (1776). Meaning "a feeling of weariness from exertion" is from 1719. Of metals or other materials under strain, from 1877.
fatigue (v.)youdaoicibaDictYouDict
1690s, from French fatiguer "to tire" (15c.), from fatigue (see fatigue (n.)). Earlier in same sense was fatigate (1530s), from Latin fatigatus, past participle of fatigare. Related: Fatigued; fatiguing; fatigation (c. 1500).