- (music) A theatrical work, combining drama, music, song and sometimes dance.
- (music) The score for such a work.
- A building designed for the performance of such works; an opera house.
- 1907, Robert William Chambers, chapter VI, in The Younger Set, New York, N.Y.: D. Appleton & Company, OCLC 24962326 ↗:
- “I don't mean all of your friends—only a small proportion—which, however, connects your circle with that deadly, idle, brainless bunch—the insolent chatterers at the opera, the gorged dowagers, […], the jewelled animals whose moral code is the code of the barnyard—!"
- A company dedicated to performing such works.
- (by extension) Any showy, melodramatic or unrealistic production resembling an opera.
- A collection of work; plural form of opus.