Socialist Republic of Vietnam vs Annam

Socialist Republic of Vietnam and Annam both are nouns.

Word	Noun	Adjective	Verb	Adverb
Socialist Republic of Vietnam	Yes	No	No	No
Annam	Yes	No	No	No

As nouns, Socialist Republic of Vietnam and Annam are synonyms defined as:

Socialist Republic of Vietnam and Annam: a communist state in Indochina on the South China Sea; achieved independence from France in 1945

Other synonyms of Socialist Republic of Vietnam include Viet Nam, Vietnam.

Socialist Republic of Vietnam (noun)	Annam (noun)
a communist state in Indochina on the South China Sea; achieved independence from France in 1945	a communist state in Indochina on the South China Sea; achieved independence from France in 1945