Great Britain vs overall

Great Britain and overall both are nouns.

Word	Noun	Adjective	Verb	Adverb
Great Britain	Yes	No	No	No
overall	Yes	Yes	No	No

Great Britain (noun)	overall (noun)
an island comprising England and Scotland and Wales	(usually plural) work clothing consisting of denim trousers (usually with a bib and shoulder straps)
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	a loose protective coverall or smock worn over ordinary clothing for dirty work

Great Britain (adjective)	overall (adjective)
	involving only main features
	including everything