dictatorial vs overweening

dictatorial

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

  • of or pertaining to a dictator 

overweening

adj
  • Unduly confident; arrogant 

  • Exaggerated, excessive. 

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