nightfall /ˈnaɪtˌfɑːl/ noun Learner's definition of NIGHTFALL
[noncount]
: the time of day when the sky gets dark : the time when night begins傍晚;黄昏 -
When nightfall came, we were still waiting for the electricity to come back on.夜幕降临时,我们还在等待供电恢复。
-
We should be back by/before nightfall. [=dark]我们应该在天黑前返回。