lamprey vs lamprey eel

lamprey and lamprey eel both are nouns.

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

As nouns, lamprey and lamprey eel are synonyms defined as:

lamprey and lamprey eel: primitive eellike freshwater or anadromous cyclostome having round sucking mouth with a rasping tongue

Other synonyms of lamprey include lamper eel.

lamprey (noun)	lamprey eel (noun)
primitive eellike freshwater or anadromous cyclostome having round sucking mouth with a rasping tongue	primitive eellike freshwater or anadromous cyclostome having round sucking mouth with a rasping tongue