Great Britain vs pony-trekking

Great Britain and pony-trekking both are nouns.

Word	Noun	Adjective	Verb	Adverb
Great Britain	Yes	No	No	No
pony-trekking	Yes	No	No	No

Great Britain (noun)	pony-trekking (noun)
an island comprising England and Scotland and Wales	a sport in which people ride across country on ponies
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