Source : Webster's Revised Unabridged Dictionary (1913)

Prelude \Pre*lude"\, v. i. [imp. & p. p. {Preluded}; p. pr. &
   vb. n. {Preluding}.] [L. praeludere, praelusum; prae before +
   ludere to play: cf. F. pr['e]luder. See {Ludicrous}.]
   To play an introduction or prelude; to give a prefatory
   performance; to serve as prelude.

         The musicians preluded on their instruments. --Sir. W.
                                                  Scott.

         We are preluding too largely, and must come at once to
         the point.                               --Jeffrey.

Prelude \Pre*lude"\, v. t.
   1. To introduce with a previous performance; to play or
      perform a prelude to; as, to prelude a concert with a
      lively air.

   2. To serve as prelude to; to precede as introductory.

            [Music] preluding some great tragedy. --Longfellow

Prelude \Pre"lude\, n. [F. pr['e]lude (cf. It. preludio, LL.
   praeludium), fr. L. prae before + ludus play. See {Prelude},
   v. t.]
   An introductory performance, preceding and preparing for the
   principal matter; a preliminary part, movement, strain, etc.;
   especially (Mus.), a strain introducing the theme or chief
   subject; a movement introductory to a fugue, yet independent;
   -- with recent composers often synonymous with overture.

         The last Georgic was a good prelude to the [AE]nis
                                                  --Addison.

         The cause is more than the prelude, the effect is more
         than the sequel, of the fact.            --Whewell.

   Syn: Preface; introduction; preliminary; preamble;
        forerunner; harbinger; precursor.

Source : WordNet®

prelude
     n 1: something that serves as a preceding event or introduces
          what follows; "training is a necessary preliminary to
          employment"; "drinks were the overture to dinner" [syn:
          {preliminary}, {overture}]
     2: music that precedes a fugue or introduces an act in an opera
     v 1: serve as a prelude or opening to
     2: play as a prelude