ardor vs frigidity

ardor

noun
  • Intense heat. 

  • Great warmth of feeling; fervor; passion. 

  • Spirit; enthusiasm; passion. 

frigidity

noun
  • The state of being frigid; coldness; lack of heat. 

  • Coldness of feeling, manner or quality; lack of ardor, animation or vivacity. 

  • Lack of natural heat and vigor of body; impotency. 

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