Dictionary.com
Thesaurus.com
Synonyms

good night

1 American  

interjection

  1. an expression of farewell used in parting at nighttime or when going to sleep.


good-night 2 American  
[good-nahyt] / ˌgʊdˈnaɪt /

noun

  1. a farewell or leave-taking.

    He said his good-nights before leaving the party.


good night British  
  1. a conventional expression of farewell, or, rarely, of greeting, used in the late afternoon, the evening, or at night, esp when departing to bed

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

good night Idioms  
  1. Expression of farewell used when parting at night or when going to sleep, as in He stood at the door, saying good night to each of the departing guests , or Mother came to tuck the children in and kiss them good night . [Late 1300s]

  2. Exclamation of surprise or irritation, as in Good night, Joe!—You can't mean what you said , or Good night, Anne—it's time you learned how to throw a ball . [Late 1800s]


Etymology

Origin of good night

Middle English word dating back to 1325–75

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Before he returned to his wife and children, David told Mother to ignore the nighttime noises and get a good night’s sleep.

From Literature

“I want to get a good night’s sleep. It should be dry enough to work in the fields tomorrow.”

From Literature

I told him good night and pretended to go back to the camp, but when he was out of sight, I slipped into the darkness of the trees.

From Literature

And to have that experience of saying good night to somebody and having them leave and then find out the next day that they’re gone.

From Salon

Yet rumba is so much more than the soundtrack to a good night out on the town.

From Barron's