rock barnacle vs cirriped

rock barnacle and cirriped both are nouns.

Word	Noun	Adjective	Verb	Adverb
rock barnacle	Yes	No	No	No
cirriped	Yes	No	No	No

As nouns, cirriped is a hypernym of rock barnacle; that is, cirriped is a word with a broader meaning than rock barnacle:

rock barnacle: barnacle that attaches to rocks especially in intertidal zones
cirriped: marine crustaceans with feathery food-catching appendages; free-swimming as larvae; as adults form a hard shell and live attached to submerged surfaces

Other hypernyms of rock barnacle include barnacle, cirripede.

rock barnacle (noun)	cirriped (noun)
barnacle that attaches to rocks especially in intertidal zones	marine crustaceans with feathery food-catching appendages; free-swimming as larvae; as adults form a hard shell and live attached to submerged surfaces