ardor vs avidness

ardor and avidness both are nouns.

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

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

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

Other hypernyms of ardor include avidity, eagerness, keenness.

ardor (noun)	avidness (noun)
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