obverse vs ventral

obverse

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

  • Corresponding; complementary. 

  • 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. 

ventral

adj
  • On the front side of the human body, or the corresponding surface of an animal, usually the lower surface. 

  • Related to the abdomen or stomach. 

  • On or relating to the bottom portion of either foot and/or hand. 

noun
  • Any of the enlarged and transversely elongated scales that extend down the underside of a snake's body from the neck to the anal scale. 

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