common roundworm vs roundworm

common roundworm and roundworm both are nouns.

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

As nouns, roundworm is a hypernym of common roundworm; that is, roundworm is a word with a broader meaning than common roundworm:

common roundworm: intestinal parasite of humans and pigs
roundworm: unsegmented worms with elongated rounded body pointed at both ends; mostly free-living but some are parasitic

Other hypernyms of common roundworm include nematode, nematode worm.

common roundworm (noun)	roundworm (noun)
intestinal parasite of humans and pigs	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