The Collaborative International Dictionary of English v.0.48:

Acclamation \Ac`cla*ma"tion\, n. [L. acclamatio: cf. F.
   acclamation.]
   1. A shout of approbation, favor, or assent; eager expression
      of approval; loud applause.
      [1913 Webster]

            On such a day, a holiday having been voted by
            acclamation, an ordinary walk would not satisfy the
            children.                             --Southey.
      [1913 Webster]

   2. (Antiq.) A representation, in sculpture or on medals, of
      people expressing joy.
      [1913 Webster]

   3. In parliamentary usage, the act or method of voting orally
      and by groups rather than by ballot, esp. in elections;
      specif. (R. C. Ch.), the election of a pope or other
      ecclesiastic by unanimous consent of the electors, without
      a ballot.
      [Webster 1913 Suppl.]

   Acclamation medals are those on which laudatory
      acclamations are recorded. --Elmes.
      [1913 Webster]

WordNet (r) 3.0 (2006):

acclamation
    n 1: enthusiastic approval; "the book met with modest acclaim";
         "he acknowledged the plaudits of the crowd"; "they gave him
         more eclat than he really deserved" [syn: acclaim,
         acclamation, plaudits, plaudit, eclat]

Moby Thesaurus II by Grady Ward, 1.0:

54 Moby Thesaurus words for "acclamation":
   acclaim, accord, accordance, agreement, agreement of all, applause,
   big hand, burst of applause, cheer, chorus, clap, clapping,
   clapping of hands, common assent, common consent, concert, concord,
   concordance, concurrence, consensus, consensus gentium,
   consensus of opinion, consensus omnium, consent, consentaneity,
   eclat, encore, general acclamation, general agreement,
   general consent, general voice, hand, handclap, handclapping,
   harmony, like-mindedness, meeting of minds, mutual understanding,
   one accord, one voice, ovation, plaudit, plaudits, popularity,
   round of applause, same mind, single voice, thunder of applause,
   total agreement, unanimity, unanimousness, understanding, unison,
   universal agreement