The Collaborative International Dictionary of English v.0.48:

Cheer \Cheer\, v. t. [imp. & p. p. Cheered (ch[=e]rd); p. pr.
   & vb. n. cheering.]
   1. To cause to rejoice; to gladden; to make cheerful; --
      often with up. --Cowpe.
      [1913 Webster]

   2. To infuse life, courage, animation, or hope, into; to
      inspirit; to solace or comfort.
      [1913 Webster]

            The proud he tamed, the penitent he cheered.
                                                  --Dryden.
      [1913 Webster]

   3. To salute or applaud with cheers; to urge on by cheers;
      as, to cheer hounds in a chase.
      [1913 Webster]

   To cheer ship, to salute a passing ship by cheers of
      sailors stationed in the rigging.

   Syn: To gladden; encourage; inspirit; comfort; console;
        enliven; refresh; exhilarate; animate; applaud.
        [1913 Webster]

WordNet (r) 3.0 (2006):

cheering
    adj 1: providing freedom from worry [syn: comforting,
           cheering, satisfying]
    n 1: encouragement in the form of cheers from spectators; "it's
         all over but the shouting" [syn: cheering, shouting]

Moby Thesaurus II by Grady Ward, 1.0:

51 Moby Thesaurus words for "cheering":
   animating, assuring, auspicious, bracing, bright with promise,
   brisk, cheerful, cheery, comforting, condolatory, condolent,
   condoling, consolatory, consoling, cordial, crisp, crispy,
   encouraging, energizing, enlivening, exhilarating, favorable,
   fresh, full of promise, glad, gladdening, heart-warming,
   heartening, hospitable, inspiring, inspiriting, invigorating,
   joyful, looking up, of good comfort, of promise, pregnant of good,
   promising, propitious, reassuring, refreshful, refreshing,
   regaling, relieving, rousing, stimulating, supportive, sympathetic,
   tonic, zestful, zesty