doubtful vs genuine

doubtful

noun
  • A doubtful person or thing. 

adj
  • Experiencing or showing doubt, sceptical. 

  • Subject to, or causing doubt. 

  • Improbable or unlikely. 

  • Unclear or unreliable. 

  • Suspicious, or of dubious character. 

  • Undecided or of uncertain outcome. 

genuine

adj
  • Not counterfeit, spurious, false, or adulterated 

  • Belonging to, or proceeding from the original stock; native 

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