grope vs trephine

grope

verb
  • To touch (another person) closely and (especially) sexually. 

  • To intentionally and inappropriately touch or rub against another person, in such a manner as to make the contact appear accidental, for the purpose of one's sexual gratification. 

  • To search or attempt to find something in the dark, or, as a blind person, by feeling; to move about hesitatingly, as in darkness or obscurity; to feel one's way, as with the hands, when one can not see. 

noun
  • An act of groping, especially sexually. 

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 grope and trephine occurred in a corpus of books? (source: Google Ngram Viewer )