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]