magnum opus
/ˈmægnəmˈəʊpəs/noun
(pl. magnum opuses或magna opera /ˌmægnəˈəʊpərə/)
- a large and important work of art, music, or literature, especially one regarded as the most important work of an artist or writer（尤指艺术家或作家最重要的）杰作; 巨著, 鸿篇。
词源
late 18th cent.: from Latin， 'great work'.