chicken roundworm vs roundworm

chicken roundworm and roundworm both are nouns.

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

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

chicken roundworm: intestinal parasite of domestic fowl
roundworm: unsegmented worms with elongated rounded body pointed at both ends; mostly free-living but some are parasitic

Other hypernyms of chicken roundworm include nematode, nematode worm.

chicken roundworm (noun)	roundworm (noun)
intestinal parasite of domestic fowl	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