trepan vs wormhole

trepan

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. 

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. 

wormhole

verb
  • To make porous or permeable through the formation of small holes or tunnels. 

noun
  • A location in a monitor program containing the address of a routine, allowing the user to substitute different functionality. 

  • A hole burrowed by a worm. 

  • A hypothetical shortcut between two points in spacetime, permitting faster-than-light travel and sometimes time travel. 

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