antithetical vs diametric

antithetical

adj
  • Pertaining to antithesis, or opposition of words and sentiments; containing, or of the nature of, antithesis; contrasted. 

diametric

adj
  • Directly opposing. 

  • Of or relating to a diameter; diametral. 

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