longing vs zeal

longing

noun
  • An earnest and deep, not greatly passionate, but rather melancholic desire. 

  • The buying of a financial instrument with the expectation that its value will rise 

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 longing and zeal occurred in a corpus of books? (source: Google Ngram Viewer )