reek vs mephitis

reek and mephitis both are nouns.

Word	Noun	Adjective	Verb	Adverb
reek	Yes	No	Yes	No
mephitis	Yes	No	No	No

As nouns, reek and mephitis are synonyms defined as:

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

reek (noun)	mephitis (noun)
a distinctive odor that is offensively unpleasant	a distinctive odor that is offensively unpleasant
	a poisonous or foul smelling gas emitted from the earth

reek (verb)	mephitis (verb)
be wet with sweat or blood, as of one's face
smell badly and offensively
have an element suggestive (of something)
give off smoke, fumes, warm vapour, steam, etc.