permeate vs trephine

permeate

verb
  • To pass through the pores or interstices of; to penetrate and pass through without causing rupture or displacement; applied especially to fluids which pass through substances of loose texture 

  • To enter and spread through; to pervade. 

noun
  • Liquid that has passed through a filtration system. 

  • A watery by-product of milk production. 

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