hard case vs laughathon

hard case

noun
  • An amusing, funny, witty, or possibly strange person. May be used as a term of endearment. 

  • A tough person. 

laughathon

noun
  • Something very funny; a comedy session or period of great amusement. 

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