Great Britain vs preceptor

Great Britain and preceptor both are nouns.

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

Great Britain (noun)	preceptor (noun)
an island comprising England and Scotland and Wales	teacher at a university or college (especially at Cambridge or Oxford)
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