appetite vs colt's tooth

appetite

noun
  • Any strong desire; an eagerness or longing. 

  • Desire to eat food or consume drink. 

  • The desire for some personal gratification, either of the body or of the mind. 

colt's tooth

noun
  • Youthful desires, especially lust. 

  • One of a horse's first set of teeth. 

How often have the words appetite and colt's tooth occurred in a corpus of books? (source: Google Ngram Viewer )