Definition of "Night" :
noun: Roman goddess of night; daughter of Erebus; counterpart of Greek Nyx
"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."