eagerness vs ardor

eagerness and ardor both are nouns.

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

As nouns, ardor is a hyponym of eagerness; that is, ardor is a word with a more specific, narrower meaning than eagerness:

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

Other hyponyms of eagerness include ardour, elan, zeal.

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