kindheartedness vs sympathy

kindheartedness and sympathy both are nouns.

Word	Noun	Adjective	Verb	Adverb
kindheartedness	Yes	No	No	No
sympathy	Yes	No	No	No

As nouns, sympathy is a hypernym of kindheartedness; that is, sympathy is a word with a broader meaning than kindheartedness:

kindheartedness: sympathy arising from a kind heart
sympathy: sharing the feelings of others (especially feelings of sorrow or anguish)

Other hypernyms of kindheartedness include fellow feeling.

kindheartedness (noun)	sympathy (noun)
sympathy arising from a kind heart	an inclination to support or be loyal to or to agree with an opinion
	sharing the feelings of others (especially feelings of sorrow or anguish)
	a relation of affinity or harmony between people; whatever affects one correspondingly affects the other