aridity vs waterlessness

aridity and waterlessness both are nouns.

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

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

aridity: a deficiency of moisture (especially when resulting from a permanent absence of rainfall)
waterlessness: the condition of not containing or being covered by a liquid (especially water)

Other hypernyms of aridity include dryness, xerotes.

aridity (noun)	waterlessness (noun)
the quality of yielding nothing of value	the condition of not containing or being covered by a liquid (especially water)
a deficiency of moisture (especially when resulting from a permanent absence of rainfall)