blood fluke vs trematode worm

blood fluke and trematode worm both are nouns.

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

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

blood fluke: flatworms parasitic in the blood vessels of mammals
trematode worm: parasitic flatworms having external suckers for attaching to a host

Other hypernyms of blood fluke include fluke, trematode.

blood fluke (noun)	trematode worm (noun)
flatworms parasitic in the blood vessels of mammals	parasitic flatworms having external suckers for attaching to a host