advocate vs crusader

advocate

noun
  • A person who speaks in support of something, or someone. 

  • A person who supports others to make their voices heard, or ideally for them to speak up for themselves. 

  • Someone whose job is to speak for someone's case in a court of law; a counsel. 

  • Anyone who argues the case of another; an intercessor. 

verb
  • To appeal from an inferior court to the Court of Session. 

  • To engage in advocacy. 

  • To call a case before itself for decision. 

  • To encourage support for something. 

  • To plead in favour of; to defend by argument, before a tribunal or the public; to support, vindicate, or recommend publicly. 

crusader

noun
  • A person engaged in a crusade. 

  • 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. 

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

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