poorness vs poor

poorness and poor both are nouns.

Word	Noun	Adjective	Verb	Adverb
poorness	Yes	No	No	No
poor	Yes	Yes	No	No

poorness (noun)	poor (noun)
the quality of being poorly made or maintained	people without possessions or wealth (considered as a group)
less than adequate
the quality of being meager
the state of having little or no money and few or no material possessions

poorness (adjective)	poor (adjective)
	having little money or few possessions
	lacking in quality or substances
	characterized by or indicating poverty
	of insufficient quantity to meet a need
	deserving or inciting pity