clarify vs expiate

clarify

verb
  • To grow clear or bright; to clear up. 

  • To make clear or easily understood; to explain in order to remove doubt or obscurity. 

  • To grow or become clear or transparent; to become free from feculent impurities, as wine or other liquid under clarification. 

  • To make clear or bright by freeing from feculent matter. 

expiate

verb
  • To wind up, bring to an end. 

  • To make amends or pay the penalty for. 

  • To purify with sacred rites. 

  • To atone or make reparation for. 

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