pong vs reek

pong and reek both are nouns.

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

As nouns, reek is a hypernym of pong; that is, reek is a word with a broader meaning than pong:

Other hypernyms of pong include fetor, foetor, malodor, malodour, mephitis, stench, stink.

pong (noun)	reek (noun)
an unpleasant smell	a distinctive odor that is offensively unpleasant

pong (verb)	reek (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.