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." "Zeal, the blind conductor of the will." "Zeal's never-dying fire." "I bear them record that they have a zeal of God, but not according to knowledge." "A zeal for liberty is sometimes an eagerness to subvert with little care what shall be established."