instantaneousness vs immediateness

instantaneousness and immediateness both are nouns.

Word	Noun	Adjective	Verb	Adverb
instantaneousness	Yes	No	No	No
immediateness	Yes	No	No	No

As nouns, instantaneousness and immediateness are synonyms defined as:

instantaneousness and immediateness: the quickness of action or occurrence

Other synonyms of instantaneousness include immediacy, instancy.

instantaneousness (noun)	immediateness (noun)
the quickness of action or occurrence	the quickness of action or occurrence
	lack of an intervening or mediating agency