nematode vs roundworm

nematode and roundworm both are nouns.

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

As nouns, nematode and roundworm are synonyms defined as:

nematode and roundworm: unsegmented worms with elongated rounded body pointed at both ends; mostly free-living but some are parasitic

Other synonyms of nematode include nematode worm.

nematode (noun)	roundworm (noun)
unsegmented worms with elongated rounded body pointed at both ends; mostly free-living but some are parasitic	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