geographical region vs Bithynia

geographical region and Bithynia both are nouns.

Word	Noun	Adjective	Verb	Adverb
geographical region	Yes	No	No	No
Bithynia	Yes	No	No	No

geographical region (noun)	Bithynia (noun)
a demarcated area of the Earth	an ancient country in northwestern Asia Minor in what is now Turkey; was absorbed into the Roman Empire by the end of the 1st century BC