High Commission vs Britain

High Commission and Britain both are nouns.

Word	Noun	Adjective	Verb	Adverb
High Commission	Yes	No	No	No
Britain	Yes	No	No	No

High Commission (noun)	Britain (noun)
an embassy of one British Commonwealth country to another	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