(1)夜晚(period between sunset and sunrise，especially the hours of darkness)[C，U]：at/by/over～夜里/夜间/过夜;during/in/throughout the～ 夜间/夜里/通宵;under the cover of～趁夜;an early/a late～睡得比平时早/晚;all～整夜地;day and～日夜地;～after～一夜一夜地;have a～out 在外过一整夜;have a good (bad)～ 一夜睡得好(不好)，turn～into day 挑灯夜战; make a～of it 玩个通宵;The～grows late.夜深了。N～is falling.夜幕降临。They often work far into the～. 他们常常工作到深夜。

(2)夜晚的活动(evening or night devoted to some special purpose or event)[C;U]：the opening (last)～of a play 某戏剧的首(末)场演出;They can serve over 1500 customers on a big～. 忙的时候他们一晚上可供应1500位客人以上。We had a Mozart～yesterday evening. 昨晚我们听了莫扎特音乐专场。

→′nightly adj 晚上的，夜间的;每夜的;adv在夜间;每夜;

【用法】at night、by night、in the night、during the night、on a (...) night (...) 的用法不同。at night用于描述习惯上在天黑以后做的事：We sleep at night. (我们夜里睡觉。) by night 与at night同义，但在强调动作发生的条件或情况时使用，如：Summer temperatures here range from 25℃ by night to 32℃ by day. (这里的夏季气温夜间最低摄氏25度，白天最高摄氏32度。) in the night 通常指刚刚过去的夜晚，如：I fell asleep quickly，but deep in the night a thunderstorm awakened me. (我很快睡着了，但到深夜雷雨把我惊醒。) during the night 也可以表达这个含意，如：It rained during the night. (夜间下雨了。) on a (...) night (...) 表示更具体的夜晚，如：On the third night a blizzard struck. (在第三天夜晚来了一场暴风雪。)