geographical region vs Greater Maghreb

geographical region and Greater Maghreb both are nouns.

Word	Noun	Adjective	Verb	Adverb
geographical region	Yes	No	No	No
Greater Maghreb	Yes	No	No	No

geographical region (noun)	Greater Maghreb (noun)
a demarcated area of the Earth	the region of northwest Africa comprising the Atlas Mountains and the coastlands of Morocco and Algeria and Tunisia