Definition of "Night" :

noun: Roman goddess of night; daughter of Erebus; counterpart of Greek Nyx

noun: darkness

"It vanished into the night."

noun: the dark part of the diurnal cycle considered a time unit

"Three nights later he collapsed."

noun: the time after sunset and before sunrise while it is dark outside

noun: the time between sunset and midnight

"He watched television every night."

noun: the period spent sleeping

"I had a restless night."

noun: a period of ignorance or backwardness or gloom

noun: a shortening of nightfall

"They worked from morning to night."