This is the 1345th most frequent French word.
opus
A musical or artistic work, often numbered to indicate its place in an artist's catalog.
Here, the word 'opus' is used metaphorically to refer to a musical work or album.
Son dernier opus contient plusieurs chansons émouvantes.
His latest opus contains several moving songs.
In this sentence, 'opus' refers to a singular piece of literary work by the writer.
Le chef-d'œuvre de cet écrivain est son unique opus achevé.
The masterpiece of this writer is his unique completed opus.
The term 'opus' is used to describe an individual installment or volume within a series of works.