ardor vs eagerness

ardor and eagerness both are nouns.

Word	Noun	Adjective	Verb	Adverb
ardor	Yes	No	No	No
eagerness	Yes	No	No	No

As nouns, eagerness is a hypernym of ardor; that is, eagerness is a word with a broader meaning than ardor:

ardor: a feeling of strong eagerness (usually in favor of a person or cause)
eagerness: a positive feeling of wanting to push ahead with something

Other hypernyms of ardor include avidity, avidness, keenness.

ardor (noun)	eagerness (noun)
intense feeling of love	prompt willingness
a feeling of strong eagerness (usually in favor of a person or cause)	a positive feeling of wanting to push ahead with something
feelings of great warmth and intensity