geographic region vs Piedmont

geographic region and Piedmont both are nouns.

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

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