incongruity vs incongruousness

incongruity and incongruousness both are nouns.

Word	Noun	Adjective	Verb	Adverb
incongruity	Yes	No	No	No
incongruousness	Yes	No	No	No

As nouns, incongruity and incongruousness are synonyms defined as:

incongruity and incongruousness: the quality of disagreeing; being unsuitable and inappropriate

incongruity (noun)	incongruousness (noun)
the quality of disagreeing; being unsuitable and inappropriate	the quality of disagreeing; being unsuitable and inappropriate