ringworm vs roundworm

ringworm and roundworm both are nouns.

Word	Noun	Adjective	Verb	Adverb
ringworm	Yes	No	No	No
roundworm	Yes	No	No	No

As nouns, ringworm and roundworm are synonyms defined as:

ringworm and roundworm: infections of the skin or nails caused by fungi and appearing as itching circular patches

Other synonyms of ringworm include tinea.

ringworm (noun)	roundworm (noun)
infections of the skin or nails caused by fungi and appearing as itching circular patches	unsegmented worms with elongated rounded body pointed at both ends; mostly free-living but some are parasitic
	infections of the skin or nails caused by fungi and appearing as itching circular patches