importune vs nonplus

importune

verb
  • To bother, irritate, trouble. 

  • To harass with persistent requests. 

  • To approach to offer one's services as a prostitute, or otherwise make improper proposals. 

nonplus

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

noun
  • A state of bewilderment or perplexity. 

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