The Collaborative International Dictionary of English v.0.48:

Truce \Truce\, n. [OE. trewes, triwes, treowes, pl. of trewe a
   truce, properly, pledge of fidelity, truth, AS. tre['o]w
   fidelity, faith, troth. See True.]
   1. (Mil.) A suspension of arms by agreement of the commanders
      of opposing forces; a temporary cessation of hostilities,
      for negotiation or other purpose; an armistice.
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   2. Hence, intermission of action, pain, or contest; temporary
      cessation; short quiet.
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            Where he may likeliest find
            Truce to his restless thoughts.       --Milton.
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   Flag of truce (Mil.), a white flag carried or exhibited by
      one of the hostile parties, during the flying of which
      hostilities are suspended.

   Truce of God, a suspension of arms promulgated by the
      church, which occasionally took place in the Middle Ages,
      putting a stop to private hostilities at or within certain
      periods.
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WordNet (r) 3.0 (2006):

flag of truce
    n 1: flag consisting of a piece of white cloth that is hoisted
         to signal surrender or to ask for a truce [syn: white
         flag, flag of truce]