EC vs international organization

EC and international organization both are nouns.

Word	Noun	Adjective	Verb	Adverb
EC	Yes	No	No	No
international organization	Yes	No	No	No

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

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

EC (noun)	international organization (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