opera¹

n.

歌剧[C]
Carmen is a well-known opera.
《卡门》是一部有名的歌剧。
歌剧艺术；歌剧业[U]
Opera is a blend of all the performing arts -- songs, instrumental music, dance and drama.
歌剧艺术集所有表演艺术（歌，乐器，舞蹈和戏剧）为一体。
歌剧院[C]
She was once the best singer at the Paris Opera.
她曾是巴黎歌剧院最好的歌唱家。

opera²

opus

n.

以上来源于：《英汉大辞典》

n.

a dramatic work in one or more acts that is set to music for singers and instrumentalists.

▸an opera house.

C17: from Ital., from L., lit. ‘labour, work’.

plural form of opus.

以上来源于：《简明牛津英语词典》