Ar"dor (#), n. [L. ardor, fr. ardere to burn: cf. OF. ardor, ardur, F. ardeur.] [Spelt also ardour.]
Heat, in a literal sense; as, the ardor of the sun's rays.
Warmth or heat of passion or affection; eagerness; zeal; as, he pursues study with ardor; the fought with ardor; martial ardor.
Bright and effulgent spirits; seraphim. [Thus used by Milton.]
Syn. -- Fervor; warmth; eagerness. See Fervor.
© Webster 1913.