donation vs sweetener

donation

noun
  • A voluntary gift or contribution for a specific cause. 

  • The act of giving or bestowing; a grant. 

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 donation and sweetener occurred in a corpus of books? (source: Google Ngram Viewer )