deaf vs heedless

deaf is a noun but heedless is not a noun.

Word	Noun	Adjective	Verb	Adverb
deaf	Yes	Yes	Yes	No
heedless	No	Yes	No	No

deaf (noun)	heedless (noun)
people who have severe hearing impairments

deaf (adjective)	heedless (adjective)
lacking or deprived of the sense of hearing wholly or in part	marked by or paying little heed or attention
(usually followed by `to') unwilling or refusing to pay heed	characterized by careless unconcern

deaf (verb)	heedless (verb)
make or render deaf