callous vs callousness

callous is not a noun while callousness is a noun.

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

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

callous (adjective)	callousness (adjective)
emotionally hardened
having calluses; having skin made tough and thick through wear

callous (verb)	callousness (verb)
make insensitive or callous; deaden feelings or morals