keenness vs elan

keenness and elan both are nouns.

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

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

Other hyponyms of keenness include ardor, ardour, zeal.

keenness (noun)	elan (noun)
thinness of edge or fineness of point	enthusiastic and assured vigor and liveliness
a quick and penetrating intelligence	distinctive and stylish elegance
a positive feeling of wanting to push ahead with something	a feeling of strong eagerness (usually in favor of a person or cause)