unadaptability vs inability

unadaptability and inability both are nouns.

Word	Noun	Adjective	Verb	Adverb
unadaptability	Yes	No	No	No
inability	Yes	No	No	No

As nouns, inability is a hypernym of unadaptability; that is, inability is a word with a broader meaning than unadaptability:

unadaptability: the inability to change or be changed to fit changed circumstances
inability: lacking the power to perform

Other hypernyms of unadaptability include unfitness.

unadaptability (noun)	inability (noun)
the inability to change or be changed to fit changed circumstances	lacking the power to perform
	lack of ability (especially mental ability) to do something