The Collaborative International Dictionary of English v.0.48:

Plaudit \Plau"dit\, n. [From L. plaudite do ye praise (which was
   said by players at the end of a performance), 2d pers. pl.
   imperative of plaudere. Cf. Plausible.]
   A mark or expression of applause; praise bestowed.
   [1913 Webster]

         Not in the shouts and plaudits of the throng.
                                                  --Longfellow.
   [1913 Webster]

   Syn: Acclamation; applause; encomium; commendation;
        approbation; approval.
        [1913 Webster]

WordNet (r) 3.0 (2006):

plaudit
    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:

18 Moby Thesaurus words for "plaudit":
   acclaim, acclamation, applause, big hand, burst of applause, cheer,
   clap, clapping, clapping of hands, eclat, encore, hand, handclap,
   handclapping, ovation, popularity, round of applause,
   thunder of applause