desire vs thirstiness

desire and thirstiness both are nouns.

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

As nouns, thirstiness is a hyponym of desire; that is, thirstiness is a word with a more specific, narrower meaning than desire:

Other hyponyms of desire include hunger, hungriness, thirst, greed.

desire (noun)	thirstiness (noun)
an inclination to want things	strong desire for something (not food or drink)
the feeling that accompanies an unsatisfied state	a physiological need to drink
something that is desired	a deficiency of moisture (especially when resulting from a permanent absence of rainfall)

desire (verb)	thirstiness (verb)
feel or have a desire for; want strongly
express a desire for
expect and wish