goose vs barnacle goose

goose and barnacle goose both are nouns.

Word	Noun	Adjective	Verb	Adverb
goose	Yes	No	Yes	No
barnacle goose	Yes	No	No	No

As nouns, barnacle goose is a hyponym of goose; that is, barnacle goose is a word with a more specific, narrower meaning than goose:

goose: web-footed long-necked typically gregarious migratory aquatic birds usually larger and less aquatic than ducks
barnacle goose: European goose smaller than the brant; breeds in the far north

goose (noun)	barnacle goose (noun)
web-footed long-necked typically gregarious migratory aquatic birds usually larger and less aquatic than ducks	European goose smaller than the brant; breeds in the far north
flesh of a goose (domestic or wild)
a man who is a stupid incompetent fool