malodour vs fetor

malodour and fetor both are nouns.

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

As nouns, malodour and fetor are synonyms defined as:

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

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