contrariant vs diametral

contrariant

adj
  • contrary; opposed; antagonistic; contradictory 

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

diametral

adj
  • Contrary; diametrically opposed. 

  • Of, relating to, or measured across a diameter. 

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