expatiate vs postil

expatiate

verb
  • To write or speak at length; to be copious in argument or discussion. 

  • To range at large, or without restraint. 

postil

verb
  • To write postils, or marginal notes; to comment; to postillate. 

  • To write marginal or explanatory notes on; to gloss. 

noun
  • A marginal note. 

  • A collection of homilies. 

  • A short homily or commentary on a passage of Scripture. 

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