appendage vs lessening

appendage

noun
  • A part that is joined to something larger. 

  • An external body part that projects from the body. 

  • A natural prolongation or projection from a part of any organism. 

lessening

noun
  • A growing lesser; reduction or decrease. 

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