Source : Webster's Revised Unabridged Dictionary (1913)

Overture \O"ver*ture\, [OF. overture, F. ouverture, fr. OF.
   ovrir, F. ouvrir. See {Overt}.]
   1. An opening or aperture; a recess; a recess; a chamber.
      [Obs.] --Spenser. ``The cave's inmost overture.''
      --Chapman.

   2. Disclosure; discovery; revelation. [Obs.]

            It was he That made the overture of thy treasons to
            us.                                   --Shak.

   3. A proposal; an offer; a proposition formally submitted for
      consideration, acceptance, or rejection. ``The great
      overture of the gospel.'' --Barrow.

   4. (Mus.) A composition, for a full orchestra, designed as an
      introduction to an oratorio, opera, or ballet, or as an
      independent piece; -- called in the latter case a {concert
      overture}.