the period of darkness between sunset and sunrise.
2.
the beginning of this period; nightfall.
3.
the darkness of night; the dark.
4.
a condition or time of obscurity, ignorance, sinfulness, misfortune, etc.: the long night of European history known as the Dark Ages.
5.
(sometimes initial capital letter) an evening used or set aside for a particular event, celebration, or other special purpose: a night on the town; poker night; New Year's Night.
–adjective
6.
of or pertaining to night: the night hours.
7.
occurring, appearing, or seen at night: a night raid; a night bloomer.
8.
used or designed to be used at night: to take a night coach; the night entrance.
9.
working at night: night nurse; the night shift.
10.
active at night: the night feeders of the jungle.
—Idiom
11.
night and day, unceasingly; continually: She worked night and day until the job was done.
Origin: bef. 900; ME; OE niht, neaht, c. G Nacht, Goth nahts, L nox (s. noct-), Gk nýx (s. nykt-)
The period between sunset and sunrise, especially the hours of darkness.
This period considered as a unit of time: for two nights running.
This period considered from its conditions: a rainy night.
The period between evening and bedtime.
This period considered from its activities: a night at the opera.
This period set aside for a specific purpose: Parents' Night at school.
The period between bedtime and morning: spent the night at a motel.
One's sleep during this period: had a restless night.
A time or condition of gloom, obscurity, ignorance, or despair: "In a real dark night of the soul it is always three o'clock in the morning"(F. Scott Fitzgerald).
A time or condition marked by absence of moral or ethical values: "He never would have let us go untroubled into the night of private greed"(Anthony Lewis).
The period between dusk and midnight of a given day: either late Thursday night or early Friday morning.
The period between evening and bedtime.
This period considered from its activities: a night at the opera.
This period set aside for a specific purpose: Parents' Night at school.
The period between bedtime and morning: spent the night at a motel.
One's sleep during this period: had a restless night.
A time or condition of gloom, obscurity, ignorance, or despair: "In a real dark night of the soul it is always three o'clock in the morning"(F. Scott Fitzgerald).
A time or condition marked by absence of moral or ethical values: "He never would have let us go untroubled into the night of private greed"(Anthony Lewis).
The period between bedtime and morning: spent the night at a motel.
One's sleep during this period: had a restless night.
A time or condition of gloom, obscurity, ignorance, or despair: "In a real dark night of the soul it is always three o'clock in the morning"(F. Scott Fitzgerald).
A time or condition marked by absence of moral or ethical values: "He never would have let us go untroubled into the night of private greed"(Anthony Lewis).
Nightfall: worked from morning to night.
Darkness: vanished into the night.
A time or condition of gloom, obscurity, ignorance, or despair: "In a real dark night of the soul it is always three o'clock in the morning"(F. Scott Fitzgerald).
A time or condition marked by absence of moral or ethical values: "He never would have let us go untroubled into the night of private greed"(Anthony Lewis).
adj.
Of or relating to the night: the night air.
Intended for use at night: a night light.
Working during the night: the night nurse.
Active chiefly at night: night prowlers.
Occurring after dark: night baseball.
[Middle English, from Old English niht; see nekw-t- in Indo-European roots.]
nights (nīts) adv. During the nighttime on every day or most days: She works nights at the restaurant.
[nahyts] 
) an evening used or set aside for a particular event, celebration, or other special purpose: a night on the town; poker night; New Year's Night. 
