malodor vs fetor

malodor and fetor both are nouns.

Word	Noun	Adjective	Verb	Adverb
malodor	Yes	No	No	No
fetor	Yes	No	No	No

As nouns, malodor and fetor are synonyms defined as:

Other synonyms of malodor include foetor, malodour, mephitis, reek, stench, stink.

malodor (noun)	fetor (noun)
a distinctive odor that is offensively unpleasant	a distinctive odor that is offensively unpleasant