propitiation vs retrievement

propitiation

noun
  • The death of Christ as a basis for the forgiveness of sin. 

  • The act of propitiating; placation, atonement, similar to expiation but with the added concept of appeasement of anger. 

retrievement

noun
  • retrieval 

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