- (Latin) IPA(key): /ˌmaŋnũː ˈopus/
- (Received Pronunciation) enPR: măg'nəm ōʹpəs, IPA(key): /ˌmæɡnəm ˈəʊpəs/
- (US) enPR: măg'nəm ōʹpəs, IPA(key): /ˌmæɡnəm ˈoʊpəs/
- A great or important work of literature, music or art, a masterpiece.
- The best, most popular, or most renowned achievement of an author or artist, representing their major life effort.
- The 1949 novel Nineteen Eighty-Four is widely considered to be George Orwell's magnum opus.
- (alchemy) The process of working with the prima materia to create the philosopher's stone.
The Latin plural magna opera may be preferred in some academic and literary contexts, in popular usage the English-style plural magnum opuses is more common. The plural magnum opi, although rare and likely regarded as incorrect in formal works, does see some use.
- ^ The American Heritage® Dictionary of the English Language [Fourth Edition]