castoff vs treachery

castoff

noun
  • Something that has been rejected or discarded; a reject. 

adj
  • discarded, rejected. 

treachery

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

  • An act or instance of treachery. 

  • Treason. 

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

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