absoluteness vs unchangingness

absoluteness and unchangingness both are nouns.

Word	Noun	Adjective	Verb	Adverb
absoluteness	Yes	No	No	No
unchangingness	Yes	No	No	No

As nouns, unchangingness is a hypernym of absoluteness; that is, unchangingness is a word with a broader meaning than absoluteness:

absoluteness: the quality of being absolute
unchangingness: the quality of being unchangeable; having a marked tendency to remain unchanged

Other hypernyms of absoluteness include changelessness, unchangeability, unchangeableness.

absoluteness (noun)	unchangingness (noun)
the quality of being absolute	the quality of being unchangeable; having a marked tendency to remain unchanged
the quality of being complete or utter or extreme