Source : Webster's Revised Unabridged Dictionary (1913)

Soothe \Soothe\, v. t. [imp. & p. p. {Soothed}; p. pr. & vb. n.
   {Soothing}.] [Originally, to assent to as true; OE. so?ien to
   verify, AS. ges??ian to prove the truth of, to bear witness.
   See {Sooth}, a.]
   1. To assent to as true. [Obs.] --Testament of Love.

   2. To assent to; to comply with; to gratify; to humor by
      compliance; to please with blandishments or soft words; to
      flatter.

            Good, my lord, soothe him, let him take the fellow.
                                                  --Shak.

            I've tried the force of every reason on him, Soothed
            and caressed, been angry, soothed again. --Addison.

   3. To assuage; to mollify; to calm; to comfort; as, to soothe
      a crying child; to soothe one's sorrows.

            Music hath charms to soothe the savage breast, To
            soften rocks, or bend a knotted oak.  --Congreve.

            Though the sound of Fame May for a moment soothe, it
            can not slake The fever of vain longing. --Byron.

   Syn: To soften; assuage; allay; compose; mollify;
        tranquilize; pacify; mitigate.

Source : WordNet®

soothe
     v 1: give moral or emotional strength to [syn: {comfort}, {console},
           {solace}]
     2: cause to feel better; "the medicine soothes the pain of the
        inflammation" [ant: {irritate}]