wheat eel vs nematode worm

wheat eel and nematode worm both are nouns.

Word	Noun	Adjective	Verb	Adverb
wheat eel	Yes	No	No	No
nematode worm	Yes	No	No	No

As nouns, nematode worm is a hypernym of wheat eel; that is, nematode worm is a word with a broader meaning than wheat eel:

wheat eel: small roundworm parasitic on wheat
nematode worm: unsegmented worms with elongated rounded body pointed at both ends; mostly free-living but some are parasitic

Other hypernyms of wheat eel include nematode, roundworm.

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