(countable) The period between sunset and sunrise, when a location
faces far away from the sun, thus when the
sky is dark.
(countable) An evening or Night spent at a particular activity.
a Night on the town
(countable) A Night (and part of the days before and after it) spent in a hotel or other accommodation.
We stayed at the Hilton for five nights.
(countable) The
quality of
sleep obtained during a night.
I had a bad Night last night.
(uncountable) Nightfall.
from noon till night
(uncountable) Darkness.
The cat disappeared into the night.