epitaph vs etching

epitaph

verb
  • To write or speak after the manner of an epitaph. 

  • To commemorate by an epitaph. 

noun
  • An inscription on a gravestone in memory of the deceased. 

  • A poem or other short text written in memory of a deceased person. 

etching

noun
  • The art of producing an image from a metal plate into which an image or text has been etched with acid. 

  • The image created by this process. 

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