fervor for a person, cause, or object; eager desire or endeavor; enthusiastic diligence; ardor.

noun

apathy , indifference , lethargy

noun

alacrity , ardor , bustle , determination , devotion , diligence , dispatch , drive , eagerness , earnestness , enterprise , fanaticism , fervor , fierceness , fire , gusto , hustle , inclination , initiative , intensity , intentness , keenness , mania , passion , perseverance , push , readiness , sincerity , spirit , stick-to-itiveness , urgency , vehemence , verve , warmth , what-it-takes , yen , zestnotes:zeal pertains to a keen interest while zest is keen enjoyment or added interest , zealousness , animation , assiduity , calenture , devotedness , enthusiasm , fervidity , fidelity , loyalty , rabidity , sedulity , vigor , zealotry , zest , zestfulness