propitiation vs sweetener

propitiation

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

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

sweetener

noun
  • Something given or added to added to a deal to sweeten another's attitude, especially a bribe or kickback. 

  • A shill bidder at an auction. 

  • Something added to food to sweeten its taste, especially an artificial substitute for sugar. 

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