Wikipedia definition
1. Opus numberAn Opus number (Latin sing. "work", "labour", a work of art, 1695–1705), pl. opera and opuses, abbreviated, sing. Op. and pl. Opp. refers to a number generally assigned by composers to an individual composition or set of compositions on publication, to help identify their works.
Read “Opus number” on English Wikipedia
Read “作品番号” on Japanese Wikipedia
Read “Opus number” on DBpedia


to talk about this word.