illusoriness vs falseness

illusoriness and falseness both are nouns.

Word	Noun	Adjective	Verb	Adverb
illusoriness	Yes	No	No	No
falseness	Yes	No	No	No

As nouns, falseness is a hypernym of illusoriness; that is, falseness is a word with a broader meaning than illusoriness:

illusoriness: The quality of resulting from an illusion; of being deceptive, imaginary, unreal.
falseness: the state of being false or untrue

Other hypernyms of illusoriness include falsity.

illusoriness (noun)	falseness (noun)
The quality of resulting from an illusion; of being deceptive, imaginary, unreal.	the quality of not being open or truthful; deceitful or hypocritical
	unfaithfulness by virtue of being unreliable or treacherous
	the state of being false or untrue