lamprey vs agnathan

lamprey and agnathan both are nouns.

Word	Noun	Adjective	Verb	Adverb
lamprey	Yes	No	No	No
agnathan	Yes	No	No	No

As nouns, agnathan is a hypernym of lamprey; that is, agnathan is a word with a broader meaning than lamprey:

lamprey: primitive eellike freshwater or anadromous cyclostome having round sucking mouth with a rasping tongue
agnathan: eel-shaped vertebrate without jaws or paired appendages including the cyclostomes and some extinct forms

Other hypernyms of lamprey include jawless fish, jawless vertebrate.

lamprey (noun)	agnathan (noun)
primitive eellike freshwater or anadromous cyclostome having round sucking mouth with a rasping tongue	eel-shaped vertebrate without jaws or paired appendages including the cyclostomes and some extinct forms