indeterminateness vs indeterminacy

indeterminateness and indeterminacy both are nouns.

Word	Noun	Adjective	Verb	Adverb
indeterminateness	Yes	No	No	No
indeterminacy	Yes	No	No	No

As nouns, indeterminateness and indeterminacy are synonyms defined as:

indeterminateness and indeterminacy: the quality of being vague and poorly defined

Other synonyms of indeterminateness include indefiniteness, indefinity, indetermination.

indeterminateness (noun)	indeterminacy (noun)
the quality of being vague and poorly defined	the quality of being vague and poorly defined