addendum vs tailpiece

addendum

noun
  • Something to be added; especially text added as an appendix or supplement to a document. 

  • The height by which the tooth of a gear projects beyond (outside for external, or inside for internal) the standard pitch circle or pitch line. 

  • A postscript. 

tailpiece

noun
  • An appendage or appendix. 

  • An element, often triangular, to which the strings of a violin, guitar, etc. are attached at the lower end of an instrument. 

  • A short joist between a header and a wall. 

  • The part of a telescope containing the adjusting device for the eyepiece, etc. 

  • The part of a lock that transmits motion from the hub to the latch bolt. 

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