The Collaborative International Dictionary of English v.0.48:

Peace \Peace\, n. [OE. pees, pais, OF. pais, paiz, pes, F. paix,
   L. pax, pacis, akin to pacere, paciscere, pacisci, to make an
   agreement, and prob. also pangere to fasten. Cf. Appease,
   Fair, a., Fay, v., Fang, Pacify, Pact, Pay to
   requite.]
   A state of quiet or tranquillity; freedom from disturbance or
   agitation; calm; repose; specifically:
   (a) Exemption from, or cessation of, war with public enemies.
   (b) Public quiet, order, and contentment in obedience to law.
   (c) Exemption from, or subjection of, agitating passions;
       tranquillity of mind or conscience.
   (d) Reconciliation; agreement after variance; harmony;
       concord. "The eternal love and pees." --Chaucer.
       [1913 Webster]

   Note: Peace is sometimes used as an exclamation in commanding
         silence, quiet, or order. "Peace! foolish woman."
         --Shak.
         [1913 Webster]

   At peace, in a state of peace.

   Breach of the peace. See under Breach.

   Justice of the peace. See under Justice.

   Peace of God. (Law)
   (a) A term used in wills, indictments, etc., as denoting a
       state of peace and good conduct.
   (b) (Theol.) The peace of heart which is the gift of God.

   Peace offering.
   (a) (Jewish Antiq.) A voluntary offering to God in token of
       devout homage and of a sense of friendly communion with
       Him.
   (b) A gift or service offered as satisfaction to an offended
       person.

   Peace officer, a civil officer whose duty it is to preserve
      the public peace, to prevent riots, etc., as a polliceman,
      sheriff or constable.

   To hold one's peace, to be silent; to refrain from
      speaking.

   To make one's peace with, to reconcile one with, to plead
      one's cause with, or to become reconciled with, another.
      "I will make your peace with him." --Shak.
      [1913 Webster]

WordNet (r) 3.0 (2006):

peace offering
    n 1: something offered to an adversary in the hope of obtaining
         peace [syn: peace offering, olive branch]

Moby Thesaurus II by Grady Ward, 1.0:

79 Moby Thesaurus words for "peace offering":
   Christmas present, amends, atonement, award, birthday present, box,
   burnt offering, cadeau, calumet, collection, compensation,
   composition, compromise, downing of arms, drink offering,
   empty hands, ex voto offering, expiation, expiatory offering,
   fairing, flag of truce, gift, hand of friendship, handsel,
   heave offering, hecatomb, holocaust, human sacrifice, immolation,
   incense, indemnification, indemnity, infanticide, libation,
   mactation, making amends, making good, making right, making up,
   oblation, offer of parley, offering, offertory, olive branch,
   outstretched hand, parley, peace feelers, peace offer, peace pipe,
   piacular offering, piaculum, pipe of peace, present, presentation,
   propitiation, propitiatory gift, quittance, reclamation,
   recompense, redemption, redress, reparation, restitution,
   sacramental offering, sacrifice, satisfaction, scapegoat,
   self-immolation, self-sacrifice, squaring, suttee, sutteeism,
   thank offering, tribute, truce flag, votive offering,
   white elephant, white flag, whole offering