fixedness vs fixity

fixedness and fixity both are nouns.

Word	Noun	Adjective	Verb	Adverb
fixedness	Yes	No	No	No
fixity	Yes	No	No	No

As nouns, fixedness and fixity are synonyms defined as:

fixedness and fixity: the quality of being fixed in place as by some firm attachment

Other synonyms of fixedness include fastness, fixture, secureness.

fixedness (noun)	fixity (noun)
the quality of being fixed in place as by some firm attachment	the quality of being fixed in place as by some firm attachment
the quality of being fixed and unchangeable	the quality of being incapable of mutation
remaining in place