appetite vs keenness

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. 

keenness

noun
  • eagerness or enthusiasm 

  • sharpness or cutting ability 

  • astuteness or sagacity 

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