in-joke vs wordplay

in-joke

noun
  • Synonym of inside joke (“a joke that is understood or meant to be understood only by certain people who are aware of the details”) 

wordplay

noun
  • A humorous play on words; such plays on words collectively. 

  • A witty verbal exchange; such exchanges collectively. 

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