antonym vs contrariant

antonym

noun
  • A word which has the opposite meaning of another word. 

  • A word that describes one end of a scale, while its opposite describes the other end, such as large versus small; a gradable antonym. 

contrariant

noun
  • A thing that is contrary or of opposite qualities. 

adj
  • contrary; opposed; antagonistic; contradictory 

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