Great Britain vs Crown land

Great Britain and Crown land both are nouns.

Word	Noun	Adjective	Verb	Adverb
Great Britain	Yes	No	No	No
Crown land	Yes	No	No	No

Great Britain (noun)	Crown land (noun)
an island comprising England and Scotland and Wales	land that belongs to the Crown
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