Source : Webster's Revised Unabridged Dictionary (1913)

Overfatigue \O"ver*fa*tigue"\, n.
   Excessive fatigue.

Overfatigue \O`ver*fa*tigue"\, v. t.
   To fatigue to excess; to tire out.

Source : WordNet®

overfatigue
     v : tire excessively [syn: {overtire}, {overweary}]