The Collaborative International Dictionary of English v.0.48:

Pacification \Pa*cif`i*ca"tion\, n. [L. pacificatio: cf. F.
   pacification. See Pacify.]
   The act or process of pacifying, or of making peace between
   parties at variance; reconciliation. "An embassy of
   pacification." --Bacon.
   [1913 Webster]

WordNet (r) 3.0 (2006):

pacification
    n 1: the act of appeasing someone or causing someone to be more
         favorably inclined; "a wonderful skill in the pacification
         of crying infants"; "his unsuccessful mollification of the
         mob" [syn: pacification, mollification]
    2: a treaty to cease hostilities; "peace came on November 11th"
       [syn: peace, peace treaty, pacification]
    3: actions taken by a government to defeat insurgency [syn:
       pacification, counterinsurgency]

Moby Thesaurus II by Grady Ward, 1.0:

56 Moby Thesaurus words for "pacification":
   Pax Dei, Pax Romana, Peace of God, abatement, allayment,
   alleviation, armistice, assuagement, blunting, breathing spell,
   buffer zone, calming, cease-fire, cooling-off period, damping,
   deadening, demilitarized zone, demulsion, diminution,
   dulcification, dulling, easing, falling-off, hollow truce, hushing,
   leniency, lessening, letdown, letup, lightening, loosening,
   lulling, mitigation, modulation, modus vivendi, mollification,
   neutral territory, palliation, pax in bello, peace, quietening,
   quieting, reduction, relaxation, remission, slackening, softening,
   soothing, stand-down, subduement, suspension of hostilities,
   tempering, temporary arrangement, tranquilization, treaty of peace,
   truce