Tidewater vs geographic region

Tidewater and geographic region both are nouns.

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

Tidewater (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