preceptor vs surgeon

preceptor

noun
  • A doctor who gives practical training to medical students, nurses etc. 

  • The head of a preceptory of Knights Templar. 

  • A teacher or tutor. 

surgeon

noun
  • One who performs surgery; a doctor who performs operations on people or animals. 

  • A surgeonfish. 

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