D defs.my
Entry 3 senses Webster, 1913

Ardor

/är'-dẽr/ · Ar·dor · IPA /ˈɑːɹdɚ/
01 n. Heat, in a literal sense; as, the ardor of the sun's rays.
  1. 1.
    Heat, in a literal sense; as, the ardor of the sun's rays.
  2. 2.
    Warmth or heat of passion or affection; eagerness; zeal; as, he pursues study with ardor; the fought with ardor; martial ardor.
  3. 3.
    Bright and effulgent spirits; seraphim.[Thus used by Milton.]
Syn. Fervor; warmth; eagerness. See Fervor.