Source : Webster's Revised Unabridged Dictionary (1913)

Rehearsal \Re*hears"al\ (r?*h?rs"a), n.
   The act of rehearsing; recital; narration; repetition;
   specifically, a private recital, performance, or season of
   practice, in preparation for a public exhibition or exercise.
   --Chaucer.

         In rehearsal of our Lord's Prayer.       --Hooker.

         Here's marvelous convenient place for our rehearsal.
                                                  --Shak.

   {Dress rehearsal} (Theater), a private preparatory
      performance of a drama, opera, etc., in costume.

Source : WordNet®

rehearsal
     n 1: a practice session in preparation for a public performance
          (as of a play or speech or concert); "he missed too many
          rehearsals"; "a rehearsal will be held the day before
          the wedding" [syn: {dry run}]
     2: (psychology) a form of practice; repetition of information
        (silently or aloud) in order to keep it in short-term
        memory