riveter vs trepan

riveter

noun
  • A machine or tool used to apply rivets. 

  • A person whose job is to rivet. 

trepan

noun
  • A tool used to bore through rock when sinking shafts. 

  • A surgical instrument used to remove a circular section of bone from the skull; a trephine. 

verb
  • To create a large hole by making a narrow groove outlining the shape of the hole and then removing the plug of material remaining by less expensive means. 

  • To use a trepan; to trephine. 

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