AL vs Southern United States

AL and Southern United States both are nouns.

Word	Noun	Adjective	Verb	Adverb
AL	Yes	No	No	No
Southern United States	Yes	No	No	No

As nouns, Southern United States is a hypernym of AL; that is, Southern United States is a word with a broader meaning than AL:

AL: a state in the southeastern United States on the Gulf of Mexico; one of the Confederate states during the American Civil War
Southern United States: the region of the United States lying to the south of the Mason-Dixon line

Other hypernyms of AL include South.

AL (noun)	Southern United States (noun)
a state in the southeastern United States on the Gulf of Mexico; one of the Confederate states during the American Civil War	the region of the United States lying to the south of the Mason-Dixon line