Tidewater region vs geographic region

Tidewater region and geographic region both are nouns.

Word	Noun	Adjective	Verb	Adverb
Tidewater region	Yes	No	No	No
geographic region	Yes	No	No	No

Tidewater region (noun)	geographic region (noun)
the coastal plain of the South: eastern parts of Virginia and North Carolina and South Carolina and Georgia	a demarcated area of the Earth