Webster's Revised Unabridged Dictionary · 1913

Zeal

Zeal (zēl) , noun

[French zèle; compare Portuguese & Italian zelo, Sp. zelo, celo; from Latin zelus, Greek {not transcribed}, probably akin to {not transcribed} to boil. Compare Yeast, Jealous.]

1.
Passionate ardor in the pursuit of anything; eagerness in favor of a person or cause; ardent and active interest; engagedness; enthusiasm; fervor.
Ambition varnished o'er with zeal. — Milton
Zeal, the blind conductor of the will. — Dryden
Zeal's never-dying fire. — Keble
I bear them record that they have a zeal of God, but not according to knowledge. — Rom. x. 2
A zeal for liberty is sometimes an eagerness to subvert with little care what shall be established. — Johnson
2.
A zealot. [Obsolete] — B. Jonson

Zeal , intransitive verb

To be zealous. [Obsolete & Rare] — Bacon