The spoken use of "night" as an informal, familiar Variation of "great night" (wishing a person a restful sleep) is prevalent, but I am undecided what the appropriate published equal is - if there is one. I've often employed 'Night by having an apostrophe, usually capitalized: As an example, a https://holdenwm420.webbuzzfeed.com/38297633/the-ultimate-guide-to-night-gangnam-퍼펙트가라오케-karaoke-guide