past master vs recruit

past master

noun
  • One who has an extremely high level of ability or knowledge within an area of achievement or expertise. 

  • Someone who has previously been a master at a given lodge. 

recruit

verb
  • To enroll or enlist new members or potential employees on behalf of an employer, organization, sports team, the military, etc. 

  • To become an adult or breeding-age member of a population. 

  • To prompt a protein, leucocyte. etc. to intervene in a given region of the body. 

  • To supply with new men, as an army; to fill up or make up by enlistment; also, to muster 

noun
  • A hired worker 

  • A person enlisted for service in the army; a newly enlisted soldier. 

  • A new adult or breeding-age member of a certain population. 

  • A supply of anything wasted or exhausted; a reinforcement. 

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