gunman vs thug

gunman

noun
  • A criminal armed with a gun, especially a professional killer. 

thug

noun
  • Someone with an intimidating and unseemly appearance and mannerisms, who treats others violently and roughly, often for hire. 

  • One of a band of assassins formerly active in northern India who worshipped Kali and offered their victims to her. 

  • One who, usually as a result of social disadvantage, has turned to committing crimes (e.g. selling drugs, robbery, assault, etc.) to make a living; a gangsta. 

  • An over-vigorous plant that spreads and dominates the flowerbed. 

  • A punk; a hoodlum; a hooligan. 

  • A wooden bat used in the game of miniten, fitting around the player's hand. 

verb
  • To commit acts of thuggery, to live the life of a thug, or to dress and act in a manner reminiscent of someone who does. 

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