Source : Webster's Revised Unabridged Dictionary (1913)

Appease \Ap*pease"\, v. t. [imp. & p. p. {Appealed}; p. pr. &
   vb. n. {Appeasing}.] [OE. apesen, apaisen, OF. apaisier,
   apaissier, F. apaiser, fr. a (L. ad) + OF. pais peace, F.
   paix, fr. L. pax, pacis. See {Peace}.]
   To make quiet; to calm; to reduce to a state of peace; to
   still; to pacify; to dispel (anger or hatred); as, to appease
   the tumult of the ocean, or of the passions; to appease
   hunger or thirst.

   Syn: To pacify; quiet; conciliate; propitiate; assuage;
        compose; calm; allay; hush; soothe; tranquilize.

Source : WordNet®

appease
     v 1: cause to be more favorably inclined; gain the good will of;
          "She managed to mollify the angry customer" [syn: {pacify},
           {lenify}, {conciliate}, {assuage}, {mollify}, {placate},
           {gentle}, {gruntle}]
     2: overcome or allay; "quell my hunger" [syn: {quell}, {stay}]
     3: make peace with [syn: {propitiate}]