thirstiness vs aridness

thirstiness and aridness both are nouns.

Word	Noun	Adjective	Verb	Adverb
thirstiness	Yes	No	No	No
aridness	Yes	No	No	No

As nouns, thirstiness and aridness are synonyms defined as:

thirstiness and aridness: a deficiency of moisture (especially when resulting from a permanent absence of rainfall)

Other synonyms of thirstiness include aridity.

thirstiness (noun)	aridness (noun)
strong desire for something (not food or drink)	a deficiency of moisture (especially when resulting from a permanent absence of rainfall)
a physiological need to drink
a deficiency of moisture (especially when resulting from a permanent absence of rainfall)