The Collaborative International Dictionary of English v.0.48:

Fatigue \Fa*tigue"\, n. [F., fr. fatiguer to fatigue, L.
   fatigare; cf. L. affatim sufficiently.]
   1. Weariness from bodily labor or mental exertion; lassitude
      or exhaustion of strength.
      [1913 Webster]

   2. The cause of weariness; labor; toil; as, the fatigues of
      war. --Dryden.
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   3. The weakening of a metal when subjected to repeated
      vibrations or strains.
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   Fatigue call (Mil.), a summons, by bugle or drum, to
      perform fatigue duties.

   Fatigue dress, the working dress of soldiers.

   Fatigue duty (Mil.), labor exacted from soldiers aside from
      the use of arms. --Farrow.

   Fatigue party, a party of soldiers on fatigue duty.
      [1913 Webster]

WordNet (r) 3.0 (2006):

fatigue duty
    n 1: labor of a nonmilitary kind done by soldiers (cleaning or
         digging or draining or so on); "the soldiers were put on
         fatigue to teach them a lesson"; "they were assigned to
         kitchen fatigues" [syn: fatigue duty, fatigue]