appendix vs preamble

appendix

noun
  • A text added to the end of a book or an article, containing additional information. 

  • Any process, prolongation, or projection. 

  • The vermiform appendix. 

preamble

verb
  • To speak or write a preamble; to provide a preliminary statement or set of remarks. 

noun
  • A short preliminary statement or remark, especially an explanatory introduction to a formal document or statute. 

  • A syncword. 

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