fetidness vs foulness

fetidness and foulness both are nouns.

Word	Noun	Adjective	Verb	Adverb
fetidness	Yes	No	No	No
foulness	Yes	No	No	No

As nouns, fetidness and foulness are synonyms defined as:

fetidness and foulness: the attribute of having a strong offensive smell

Other synonyms of fetidness include malodorousness, rankness, stinkiness.

fetidness (noun)	foulness (noun)
the attribute of having a strong offensive smell	the attribute of having a strong offensive smell
	(of weather) the badness of the weather
	a state characterized by foul or disgusting dirt and refuse
	disgusting wickedness and immorality