lamprey eel vs lamprey

lamprey eel and lamprey both are nouns.

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

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

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

Other synonyms of lamprey eel include lamper eel.

lamprey eel (noun)	lamprey (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