hatchet man vs iceman

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. 

iceman

noun
  • An assassin. 

  • One who is cool under pressure. 

  • A human figure carved out of ice. 

  • A man who is skilled in travelling upon ice, as among glaciers. 

  • A person who trades in ice; a person employed to deliver block ice. 

  • An ancient human male mummified in ice. 

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