- ardor, ardour, elan, zeal - a feeling of strong eagerness (usually in favor of a person or cause); "they were imbued with a revolutionary ardor"; "he felt a kind of religious zeal"
--1 is a kind of eagerness, avidity, avidness, keenness
- zeal - excessive fervor to do something or accomplish some end; "he had an absolute zeal for litigation"
--2 is a kind of ardor, ardour, fervor, fervour, fervency, fire, fervidness