1
- the period of darkness in each twenty-four hours; the time from sunset to sunrise夜, 夜晚：
a moonless night
一个没有月亮的夜晚
the office door is always locked at night.
夜里办公室的门总是锁着的。
1.1
- this as the interval between two days一夜：
supplements per person per night
每人每夜的补给品
somebody put him up for the night.
有人安排他过夜。
1.2
- the darkness of night黑夜, 夜色：
a line of watchfires stretched away into the night.
一排营火延伸在夜色中。
1.3
- poetic/literary nightfall〈诗/文〉黄昏。
2
- the period of time between afternoon and bedtime; an evening晚上：
he was not allowed to go out on weekday nights.
周一至周五晚上他都不许外出。
2.1
- with modifier an evening appointed for some activity, or spent or regarded in a certain way（安排特定活动的）夜晚; 晚间活动; 晚场; 晚会：
a Quiz Night has been organized for July 19th
7月19日已安排了一个智力竞赛晚会
wasn't it a great night out?
那（今）晚活动不是很有意思吗？
短语
night and day
- all the time; constantly整日整夜, 夜以继日：
she studied night and day.
她夜以继日地学习。
派生词
nightless
adjective词源
Old English neaht, niht, of Germanic origin; related to Dutch nacht and German Nacht, from an Indo-European root shared by Latin nox and Greek nux.