keenness vs ardor

keenness and ardor both are nouns.

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

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

keenness: 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 keenness include ardour, elan, zeal.

keenness (noun)	ardor (noun)
thinness of edge or fineness of point	intense feeling of love
a quick and penetrating intelligence	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