immovability vs fixture

immovability and fixture both are nouns.

Word	Noun	Adjective	Verb	Adverb
immovability	Yes	No	No	No
fixture	Yes	No	No	No

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

Other hyponyms of immovability include tautness, tightness, fastness, fixedness, fixity, secureness, firmness, steadiness.

immovability (noun)	fixture (noun)
not capable of being moved or rearranged	the act of putting something in working order again
	an object firmly fixed in place (especially in a household)
	the quality of being fixed in place as by some firm attachment
	a regular patron