stop up vs tampon

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

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

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

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

stop up (noun)	tampon (noun)
	plug of cotton or other absorbent material; inserted into wound or body cavity to absorb exuded fluids (especially blood)

stop up (verb)	tampon (verb)
fill or close tightly with or as if with a plug	plug with a tampon