fervor vs frigidity

fervor

noun
  • Heat. 

  • An intense, heated emotion; passion, ardor. 

  • A passionate enthusiasm for some cause. 

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 fervor and frigidity occurred in a corpus of books? (source: Google Ngram Viewer )