aridness vs thirstiness

aridness and thirstiness both are nouns.

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

As nouns, aridness and thirstiness are synonyms defined as:

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

Other synonyms of aridness include aridity.

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