cussed vs viperish

cussed

adj

  • Ill-tempered, nasty, obstinate. 

adv

  • Very, cussedly, accursedly. 

viperish

adj

  • spiteful; treacherous 

  • In the manner of a viper. 

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