double meaning vs in-joke

double meaning

noun
  • A deliberate construction that plays on two separate meanings of a word or words; a pun. 

  • The situation in which a word or phrase has two different, often opposite, meanings. For example, wicked can mean both "good" and "bad". 

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”) 

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