Definitions of night:

• noun:   darkness

  Example: "It vanished into the night"

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

  Example: "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

  Example: "He watched television every night"

• noun:   the period spent sleeping

  Example: "I had a restless night"

• noun:   a period of ignorance or backwardness or gloom
• noun:   a shortening of nightfall

  Example: "They worked from morning to night"

• noun:   Roman goddess of night; daughter of Erebus; counterpart of Greek Nyx
• name:  A surname (very rare: popularity rank in the U.S.: #69648)