pratfall vs spanker

pratfall

noun
  • A fall onto the buttocks. 

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

  • A humiliating mistake. 

verb
  • To fall on to the buttocks. 

spanker

noun
  • Someone who spanks. 

  • An instrument used to give someone a spanking or spank, such as a paddle. 

  • A fore-and-aft gaff-rigged sail on the aft-most mast of a square-rigged vessel. 

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