Webster's Revised Unabridged Dictionary · 1913

Overture

Overture

[Old French overture, French ouverture, from Old French ovrir, French ouvrir. See Overt.]

1.
An opening or aperture; a recess; a chamber. [Obsolete] — Chapman
The cave's inmost overture. — Spenser
2.
Disclosure; discovery; revelation. [Obsolete]
It was he That made the overture of thy treasons to us. — Shakespeare
3.
A proposal; an offer; a proposition formally submitted for consideration, acceptance, or rejection.
The great overture of the gospel. — Barrow
4.
(Music) 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.

Overture , transitive verb

To make an overture to; as, to overture a religious body on some subject.