South vs Deep South

South and Deep South both are nouns.

Word	Noun	Adjective	Verb	Adverb
South	Yes	No	No	No
Deep South	Yes	No	No	No

South (noun)	Deep South (noun)
the southern states that seceded from the United States in 1861	the southeastern region of the United States: South Carolina and Georgia and Alabama and Mississippi and Louisiana; prior to the American Civil War all these states produced cotton and permitted slavery
the region of the United States lying to the south of the Mason-Dixon line