dictatorialism vs dictatorship

dictatorialism

noun
  • Synonym of dictatorship 

dictatorship

noun
  • A government which exercises autocratic rule. 

  • Any household, institution, or other organization that is run under such sovereignty or autocracy. 

  • A type of government where absolute sovereignty is allotted to an individual or a small clique. 

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