magnum opus
Pronunciation:
/ˌmæɡnəm ˈəʊpəs//ˌmæɡnəm ˈoʊpəs/noun
Definitions
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.
Example: The 1949 novel Nineteen Eighty-Four is widely considered to be George Orwell's magnum opus.
The process of working with the prima materia to create the philosopher's stone.