South Africa vs African nation

South Africa and African nation both are nouns.

Word	Noun	Adjective	Verb	Adverb
South Africa	Yes	No	No	No
African nation	Yes	No	No	No

South Africa (noun)	African nation (noun)
a republic at the southernmost part of Africa; achieved independence from the United Kingdom in 1910; first European settlers were Dutch (known as Boers)	any one of the countries occupying the African continent