comforter vs expounder

comforter

noun
  • A person who comforts someone who is suffering. 

  • A pacifier. 

  • A padded cover for a bed, duvet, continental quilt. 

expounder

noun
  • A person who expounds, explains 

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