fill in vs trephine

fill in

verb
  • To fill; to replace material that is absent or has been removed. 

  • To substitute for somebody or something. 

  • To complete a form or questionnaire with requested information. 

  • To beat up; to physically assault. 

  • To inform somebody, especially to supply someone missing or missed information. 

trephine

verb
  • To perforate with a trephine. 

  • To use a trephine during surgery. 

noun
  • A surgical instrument with a cylindrical blade used to remove a circular section of tissue, f.e. bone or cornea; a trepan. 

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