funny vs knee slapper

funny

noun
  • A joke. 

  • A rowboat with both ends pointed and out of the water. 

  • A narrow clinker-built boat for sculling. 

  • A comic strip. 

adv
  • In a manner seen as being typical of a homosexual, or indicating homosexuality 

  • In an unusual manner; strangely. 

adj
  • Amusing; humorous; comical. 

  • Strange or unusual, often implying unpleasant. 

  • homosexual; gay 

  • Showing unexpected resentment. 

knee slapper

noun
  • A joke, especially one which strikes the listener or reader as particularly humorous. 

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