foisting vs treachery

foisting

noun
  • The act of something being foisted; imposition. 

treachery

noun
  • An act or instance of treachery. 

  • Treason. 

  • Deliberate, often calculated, disregard for trust or faith. 

  • The act of violating the confidence of another, usually for personal gain. 

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