unfun vs unhappy

unfun

adj

  • Not fun. 

noun

  • Lack or absence of fun; funlessness. 

unhappy

adj

  • Not happy; sad. 

  • Not satisfied; unsatisfied. 

noun

  • An individual who is not happy. 

How often have the words unfun and unhappy occurred in a corpus of books? (source: Google Ngram Viewer )