dictatorial vs disciplinarian

dictatorial

adj
  • of or pertaining to a dictator 

  • in the manner of a dictator, usually with callous disregard for others. 

disciplinarian

adj
  • Relating to discipline. 

noun
  • One who believes in discipline as a tool for regulation or control. 

  • One who exercises discipline. 

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