EU vs international organisation

EU and international organisation both are nouns.

Word	Noun	Adjective	Verb	Adverb
EU	Yes	No	No	No
international organisation	Yes	No	No	No

As nouns, international organisation is a hypernym of EU; that is, international organisation is a word with a broader meaning than EU:

EU: an international organization of European countries formed after World War II to reduce trade barriers and increase cooperation among its members
international organisation: an international alliance involving many different countries

EU (noun)	international organisation (noun)
an international organization of European countries formed after World War II to reduce trade barriers and increase cooperation among its members	an international alliance involving many different countries