hangman vs hatchet man

hangman

noun
  • An executioner responsible for hanging criminals. 

  • Someone responsible for hanging pictures and other artworks in a gallery, museum etc. 

  • A guessing game where one has to guess the word an opponent is thinking of by guessing one letter at a time, and involving the gradual drawing of a stick figure hanging from the gallows. 

hatchet man

noun
  • A male professional killer or gunman. 

  • A male who carries out brutal and unpleasant duties on behalf of another, such as firing dead wood employees. 

  • A male hatchet-wielding participant in a Chinese-American tong war. 

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