callousness vs unfeelingness

callousness and unfeelingness both are nouns.

Word	Noun	Adjective	Verb	Adverb
callousness	Yes	No	No	No
unfeelingness	Yes	No	No	No

As nouns, callousness and unfeelingness are synonyms defined as:

callousness and unfeelingness: devoid of passion or feeling; hardheartedness

Other synonyms of callousness include callosity, hardness, insensibility.

callousness (noun)	unfeelingness (noun)
devoid of passion or feeling; hardheartedness	devoid of passion or feeling; hardheartedness