steadiness vs immovableness

steadiness and immovableness both are nouns.

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

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

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

Other hypernyms of steadiness include immovability.

steadiness (noun)	immovableness (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