aridity vs poorness

aridity and poorness both are nouns.

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

As nouns, poorness is a hyponym of aridity; that is, poorness is a word with a more specific, narrower meaning than aridity:

Other hyponyms of aridity include unproductiveness.

aridity (noun)	poorness (noun)
the quality of yielding nothing of value	the quality of being poorly made or maintained
a deficiency of moisture (especially when resulting from a permanent absence of rainfall)	less than adequate
	the quality of being meager
	the state of having little or no money and few or no material possessions