liver fluke vs trematode worm

liver fluke and trematode worm both are nouns.

Word	Noun	Adjective	Verb	Adverb
liver fluke	Yes	No	No	No
trematode worm	Yes	No	No	No

As nouns, trematode worm is a hypernym of liver fluke; that is, trematode worm is a word with a broader meaning than liver fluke:

liver fluke: flatworm parasitic in liver and bile ducts of domestic animals and humans
trematode worm: parasitic flatworms having external suckers for attaching to a host

Other hypernyms of liver fluke include fluke, trematode.

liver fluke (noun)	trematode worm (noun)
flatworm parasitic in liver and bile ducts of domestic animals and humans	parasitic flatworms having external suckers for attaching to a host