gatekeeper vs slave-driver

gatekeeper

noun
  • One who gatekeeps. 

  • A person or group who controls access to something or somebody. 

  • In dissociative identity disorder, an aspect of the personality that controls access to the various identities. 

  • A person who guards or monitors passage through a gate. 

  • A common orange and brown butterfly with eyespots, Pyronia tithonus, of the family Nymphalidae. 

slave-driver

noun
  • An overseer of slaves at work; a person who puts slaves to work. 

  • An employer who demands excessive amounts of work from employees. 

How often have the words gatekeeper and slave-driver occurred in a corpus of books? (source: Google Ngram Viewer )