bar billiards vs Great Britain

bar billiards and Great Britain both are nouns.

Word	Noun	Adjective	Verb	Adverb
bar billiards	Yes	No	No	No
Great Britain	Yes	No	No	No

bar billiards (noun)	Great Britain (noun)
a table game in which short cues are used to knock balls into holes that are guarded by wooden pegs; penalties are incurred if the pegs are knocked over	an island comprising England and Scotland and Wales
	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