aridity vs thirstiness

aridity and thirstiness both are nouns.

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

As nouns, aridity and thirstiness are synonyms defined as:

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

Other synonyms of aridity include aridness.

aridity (noun)	thirstiness (noun)
the quality of yielding nothing of value	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)