noun

• (obsolete) An opening; a recess or chamber.
  "c. 1612', George Chapman, A Hymne to Hermes the cave's inmost overture"
• (obsolete) Disclosure; discovery; revelation.
  "It was he That made the overture of thy treasons to us."
• (often in plural) An approach or proposal made to initiate communication, establish a relationship etc.
  "overture of friendship"
• (Scotland) A motion placed before a legislative body, such as the General Assembly of the Church of Scotland.

verb

• (intransitive) To make overtures; to approach with a proposal.
  "For a partner setting a table in a game of “house,” an overturing child might assume the role of the father returning home from work at dinnertime rather than overturing by throwing a ball toward the child and yelling “catch.”"

adj

• (heraldry, nonstandard) Overt, that is, disclosed.
  "Crest : A falcon, wings overture."