Great Britain vs Sten gun

Great Britain and Sten gun both are nouns.

Word	Noun	Adjective	Verb	Adverb
Great Britain	Yes	No	No	No
Sten gun	Yes	No	No	No

Great Britain (noun)	Sten gun (noun)
an island comprising England and Scotland and Wales	a lightweight British submachine gun
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