Pronunciation: (ō'pus),[key] —n., —pl.o•pus•es or, esp. for 1, 2,o•pe•raPronunciation: (ō'pur-u, op'ur-u).[key] 1. a musical composition.
2. one of the compositions of a composer, usually numbered according to the order of publication.
3. a literary work or composition, as a book: Have you read her latest opus?Abbr.: op.