poorness vs aridity

poorness and aridity both are nouns.

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

As nouns, aridity is a hypernym of poorness; that is, aridity is a word with a broader meaning than poorness:

Other hypernyms of poorness include barrenness, fruitlessness.

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