Atlantic vs Gulf of Saint Lawrence

Atlantic and Gulf of Saint Lawrence both are nouns.

Word	Noun	Adjective	Verb	Adverb
Atlantic	Yes	Yes	No	No
Gulf of Saint Lawrence	Yes	No	No	No

Atlantic (noun)	Gulf of Saint Lawrence (noun)
the 2nd largest ocean; separates North and South America on the west from Europe and Africa on the east	an arm of the northwest Atlantic Ocean off the southeastern coast of Canada

Atlantic (adjective)	Gulf of Saint Lawrence (adjective)
relating to or bordering the Atlantic Ocean