steadiness vs immovability

steadiness and immovability both are nouns.

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

As nouns, immovability is a hypernym of steadiness; that is, immovability is a word with a broader meaning than steadiness:

steadiness: the quality of being steady or securely and immovably fixed in place
immovability: not capable of being moved or rearranged

Other hypernyms of steadiness include immovableness.

steadiness (noun)	immovability (noun)
the quality of being steady or securely and immovably fixed in place	not capable of being moved or rearranged
the quality of being steady--regular and unvarying
freedom from wavering or indecision; constancy of resolve or conduct