perverse vs viperish

perverse

adj
  • Obstinately in the wrong; stubborn; intractable. 

  • Morally wrong or evil; wicked; perverted. 

  • Turned aside while against something, splitting off from a thing. 

  • Ignoring the evidence or the judge's opinions. 

  • Wayward; vexing; contrary. 

verb
  • To pervert. 

viperish

adj
  • spiteful; treacherous 

  • In the manner of a viper. 

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