privative vs unhappy

privative

adj
  • consisting in the absence of something; negative 

  • causing privation; depriving 

  • indicating the absence of something 

noun
  • something that causes privation or indicates an absence 

unhappy

adj
  • Not satisfied; unsatisfied. 

  • Not happy; sad. 

noun
  • An individual who is not happy. 

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