crusader vs proponent

crusader

noun
  • An American, especially a soldier or leader who wages war against Islamist militants. 

  • the crusaders of the Middle Ages 

  • A Westerner; a Christian, especially of European descent or a missionary. 

  • A fighter in the medieval Crusades who had taken the Cross. 

  • A person engaged in a crusade. 

  • (either attributively or in the plural) The United States and its Western allies. 

proponent

noun
  • One who supports something; an advocate 

  • One who makes a proposal or proposition. 

  • One who propounds a will for probate. 

adj
  • Making proposals; proposing. 

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