opera UK /ˈɒp.ə.ɹə/US /ˈɑp.ə.ɹə/noun 6forms 2phrases 2 noun6 •a play in which the actors sing their words instead of speaking them, usually to serious music •The genre of such works, the art of composing operas. •A building designed for the performance of such works; an opera house. •A company dedicated to performing such works. •Any showy, melodramatic or unrealistic production resembling an opera. •The score for such a work. formsoperas · opere Phrases with opera horse operaA theatrical production, film, or program on radio or television depicting adventures of characters in the American Old West; a western. oat operaA film or novel depicting adventures of characters in the American Old West; a western.