defender vs expounder

defender

noun
  • Someone who defends people or property. 

  • A defendant in a civil action. 

  • A fighter who seeks to repel an attack. 

  • A lawyer who represents defendants, especially a public defender; a defense attorney (US) or defence counsel (UK). 

  • One of the players whose primary task is to prevent the opposition from scoring. 

expounder

noun
  • A person who expounds, explains 

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