blood fluke vs trematode

blood fluke and trematode both are nouns.

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

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

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

Other hypernyms of blood fluke include fluke, trematode worm.

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