eelworm vs vinegar worm

eelworm and vinegar worm both are nouns.

Word	Noun	Adjective	Verb	Adverb
eelworm	Yes	No	No	No
vinegar worm	Yes	No	No	No

As nouns, vinegar worm is a hyponym of eelworm; that is, vinegar worm is a word with a more specific, narrower meaning than eelworm:

eelworm: any of various small free-living plant-parasitic roundworms
vinegar worm: minute eelworm that feeds on organisms that cause fermentation in e.g. vinegar

Other hyponyms of eelworm include Anguillula aceti, Turbatrix aceti, vinegar eel.

eelworm (noun)	vinegar worm (noun)
any of various small free-living plant-parasitic roundworms	minute eelworm that feeds on organisms that cause fermentation in e.g. vinegar