night in WordNet English dictionary

1. the time after sunset and before sunrise while it is dark outside
   night  nighttime  dark 
   
2. darkness
   "it vanished into the night"
   night 
   
3. a period of ignorance or backwardness or gloom
   night 
   
4. the dark part of the diurnal cycle considered a time unit
   "three nights later he collapsed"
   night 
   
5. the time between sunset and midnight
   "he watched television every night"
   night 
   
6. the period spent sleeping
   "I had a restless night"
   night 
   
7. a shortening of nightfall
   "they worked from morning to night"
   night