Great Britain vs Lord High Chancellor

Great Britain and Lord High Chancellor both are nouns.

Word	Noun	Adjective	Verb	Adverb
Great Britain	Yes	No	No	No
Lord High Chancellor	Yes	No	No	No

Great Britain (noun)	Lord High Chancellor (noun)
an island comprising England and Scotland and Wales	the highest officer of the Crown who is head of the judiciary and who presides in the House of Lords
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