crack up vs waul

crack up

verb
  • To cry up; to extol. 

  • To cause to laugh heartily. 

  • To become insane; to suffer a mental breakdown. 

  • To crash an aircraft or automobile. 

  • To laugh heartily. 

adj
  • Funny; hilarious 

waul

verb
  • To wail, to cry plaintively. 

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