disinterest vs fervor

disinterest

noun
  • The absence of interest (bias or stake). 

  • An absence of interest (attention or curiosity). 

verb
  • To render disinterested. 

fervor

noun
  • Heat. 

  • An intense, heated emotion; passion, ardor. 

  • A passionate enthusiasm for some cause. 

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