burghmaster vs custodian

burghmaster

noun
  • A burgomaster. 

  • An officer who directs and lays out the meres or boundaries for the workers. 

custodian

noun
  • A person entrusted with the custody or care of something or someone; a caretaker or keeper. 

  • a janitor; a cleaner 

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