Definition from Wiktionary, the free dictionary
First coined in 1382, from Middle English zele, from Old French zel, from Late Latin zēlus, from Ancient Greek ζήλος (zēlos, “zeal, jealousy”), from ζηλόω (zēloō, “to emulate, to be jealous”). Cognate to jealous.
- The fervor or tireless devotion for a person, cause, or ideal and determination in its furtherance; diligent enthusiasm; powerful interest.
- Zeal, the blind conductor of the will.
- Bible, Romans x. 2
- I bear them record that they have a zeal of God, but not according to knowledge.
- (obsolete) A zealot.
- (Can we find and add a quotation of Ben Jonson to this entry?)
- (fervor): apathy
Derived terms 
Related terms 
fervor or devotion