Piedmont vs geographical region

Piedmont and geographical region both are nouns.

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

Piedmont (noun)	geographical region (noun)
the region of northwestern Italy; includes the Po valley	a demarcated area of the Earth
the plateau between the coastal plain and the Appalachian Mountains: parts of Virginia and North and South Carolina and Georgia and Alabama