adulterousness vs infidelity

adulterousness and infidelity both are nouns.

Word	Noun	Adjective	Verb	Adverb
adulterousness	Yes	No	No	No
infidelity	Yes	No	No	No

As nouns, infidelity is a hypernym of adulterousness; that is, infidelity is a word with a broader meaning than adulterousness:

adulterousness: The quality of being adulterous, involving sexual intercourse by a married person with someone other than their spouse.
infidelity: the quality of being unfaithful

Other hypernyms of adulterousness include immorality, unfaithfulness.

adulterousness (noun)	infidelity (noun)
The quality of being adulterous, involving sexual intercourse by a married person with someone other than their spouse.	the quality of being unfaithful