opus
/ˈəupəs; `opəs/ n
(pl opera / ˈɔpərə; `ɑpərə/)
1 musical composition numbered as one of a composer's works (work1 5b) (usu in order of publication) 编号的音乐作品（通常以出版的先後为序）
Beethoven's opus 112贝多芬第112号作品.
2 (fml 文) work of art, esp on a large scale 艺术作品; （尤指）巨著, 大作.