antithetical vs obverse

antithetical

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

obverse

adj
  • Corresponding; complementary. 

  • Having the base, or end next to the attachment, narrower than the top. 

  • Turned or facing toward the observer. 

noun
  • A proposition obtained by obversion, e.g. All men are mortal => No man is immortal. 

  • The heads side of a coin, or the side of a medal or badge that has the principal design. 

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