Southern vs Sunbelt - What's the difference?

As an adjective southern

is (not in us) from or pertaining to the southern part of any region.

a geographical region loosely described as the southern and western states of the usa where the weather is typically sunny.

(en adjective)

Of, facing, situated in, or related to the south.

Of or pertaining to a southern region, especially Southern Europe or the southern United States.

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Of a wind: blowing from the south; southerly.

* austral * meridional

* northern * boreal * septentrional

(en noun)

A geographical region loosely described as the southern and western states of the USA where the weather is typically sunny.

A political geographical region approximately the same as above, where the voting tendency of the population is right wing.