Britain vs rock salmon

Britain and rock salmon both are nouns.

Word	Noun	Adjective	Verb	Adverb
Britain	Yes	No	No	No
rock salmon	Yes	No	No	No

Britain (noun)	rock salmon (noun)
a monarchy in northwestern Europe occupying most of the British Isles; divided into England and Scotland and Wales and Northern Ireland; `Great Britain' is often used loosely to refer to the United Kingdom	any of several coarse fishes (such as dogfish or wolffish) when used as food