mistake vs pratfall

mistake

noun
  • An error; a blunder. 

  • A pitch which was intended to be pitched in a hard-to-hit location, but instead ends up in an easy-to-hit place. 

verb
  • To understand wrongly, taking one thing or person for another. 

pratfall

noun
  • A humiliating mistake. 

  • A fall onto the buttocks. 

  • A staged trip or fall, often for comedic purposes. 

verb
  • To fall on to the buttocks. 

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