murk vs nonplus

murk

verb
  • To make murky or be murky; to cloud or obscure, or to be clouded or obscured. 

  • To murder or seriously injure. 

noun
  • Darkness, or a dark or gloomy environment. 

adj
  • Dark, murky 

nonplus

verb
  • To bewilder or perplex (someone); to confound, to flummox. 

noun
  • A state of bewilderment or perplexity. 

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