stop up vs cork

stop up is not a noun while cork is a noun.

Word	Noun	Adjective	Verb	Adverb
stop up	No	No	Yes	No
cork	Yes	No	Yes	No

As verbs, cork is a hyponym of stop up; that is, cork is a word with a more specific, narrower meaning than stop up:

Other hyponyms of stop up include stopper, stopple, tampon, chink, cork up.

stop up (noun)	cork (noun)
	the plug in the mouth of a bottle (especially a wine bottle)
	a small float usually made of cork; attached to a fishing line
	outer bark of the cork oak; used for stoppers for bottles etc.
	(botany) outer tissue of bark; a protective layer of dead cells

stop up (verb)	cork (verb)
fill or close tightly with or as if with a plug	stuff with cork
	close a bottle with a cork