TX vs Red River of the South

TX and Red River of the South both are nouns.

Word	Noun	Adjective	Verb	Adverb
TX	Yes	No	No	No
Red River of the South	Yes	No	No	No

TX (noun)	Red River of the South (noun)
the second largest state; located in southwestern United States on the Gulf of Mexico	a tributary of the Mississippi River that flows eastward from Texas along the southern boundary of Oklahoma and through Louisiana