backstab vs dupe

backstab

verb
  • to attack someone (especially verbally) unfairly in a deceitful, underhand, or treacherous manner, especially when they're not present in the place or situation that it happens. (as if stabbing them in the back). See backbite. 

dupe

verb
  • To swindle, deceive, or trick. 

  • To duplicate. 

noun
  • A duplicate of an order receipt printed for kitchen staff. 

  • A duplicate of a photographic image. 

  • A person who has been deceived. 

  • A duplicate. 

  • A counterfeit; a fake. 

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