malodour vs foetor

malodour and foetor both are nouns.

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

As nouns, malodour and foetor are synonyms defined as:

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

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