callousness vs callous

callousness is a noun but callous is not a noun.

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

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

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

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