vehemence vs zeal

vehemence

noun
  • Eagerness, fervor, excessive strong feeling. 

  • A wild or turbulent ferocity or fury. 

  • An intense concentration, force or power. 

zeal

noun
  • The fervour or tireless devotion for a person, cause, or ideal and determination in its furtherance; diligent enthusiasm; powerful interest. 

  • The collective noun for a group of zebras. 

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