malodorousness vs fetidness

malodorousness and fetidness both are nouns.

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

As nouns, malodorousness and fetidness are synonyms defined as:

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

Other synonyms of malodorousness include foulness, rankness, stinkiness.

malodorousness (noun)	fetidness (noun)
the attribute of having a strong offensive smell	the attribute of having a strong offensive smell