comforter vs mainstay

comforter

noun
  • A person who comforts someone who is suffering. 

  • A pacifier. 

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

mainstay

noun
  • Someone or something that can be depended on to make a regular contribution. 

  • A stabilising rope from the top of the mainmast to the bottom of the foremast. 

  • A chief support. 

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