OVERTURE (noun) 1 an orchestral piece at the beginning of a musical work. 2 an independent orchestral composition in one movement. 3 an introduction to something more substantial. 4 (overtures) approaches made with the aim of opening negotiations or establishing a relationship. Synonyms: introduction, initiation, proposal, proposition, offer, invitation, advance. Antonyms: close, conclusion, rescission, epilogue <...>