double-dealing vs double-faced

double-dealing

adj

  • Cheating, dishonest; treacherous. 

noun

  • deceit or treachery 

double-faced

adj

  • deceitful; hypocritical; treacherous 

  • Having two functional faces. 

How often have the words double-dealing and double-faced occurred in a corpus of books? (source: Google Ngram Viewer )