‘夜幕’ literally means ‘night curtain’—a poetic, vivid metaphor for the gradual descent of darkness at dusk. The character 夜 (yè) means ‘night’, while 幕 (mù) means ‘curtain’ or ‘screen’, evoking the image of night slowly drawing shut like a theater curtain. This term is not used for literal curtains or physical objects, but exclusively to describe the atmospheric transition from day to night.

It appears frequently in descriptive writing—literature, news reports, travel blogs—and carries a calm, sometimes solemn or romantic tone. It’s more literary than conversational; you’ll rarely hear it in casual speech (where people say 天黑了 or 黄昏 instead). It often pairs with verbs like 降临 (jiànglín, ‘to descend’), 拉开 (lākāi, ‘to draw open’), or 垂下 (chuíxià, ‘to lower’), reinforcing its visual, theatrical quality.