Kingdom of Belgium vs European Union

Kingdom of Belgium and European Union both are nouns.

Word	Noun	Adjective	Verb	Adverb
Kingdom of Belgium	Yes	No	No	No
European Union	Yes	No	No	No

Kingdom of Belgium (noun)	European Union (noun)
a monarchy in northwestern Europe; headquarters for the European Union and for the North Atlantic Treaty Organization	an international organization of European countries formed after World War II to reduce trade barriers and increase cooperation among its members