assassin vs man-killer

assassin

noun
  • Any ruthless killer. 

  • A member of the Nizari Ismaili Muslim community of the Alamut Period. 

  • Someone who intentionally kills a person, especially a professional who kills a public or political figure. 

verb
  • To assassinate. 

man-killer

noun
  • A murderer. 

  • An animal that kills humans. 

  • Someone who habitually seduces men. 

How often have the words assassin and man-killer occurred in a corpus of books? (source: Google Ngram Viewer )