EU vs EEC

EU and EEC both are nouns.

Word	Noun	Adjective	Verb	Adverb
EU	Yes	No	No	No
EEC	Yes	No	No	No

As nouns, EU and EEC are synonyms defined as:

EU and EEC: an international organization of European countries formed after World War II to reduce trade barriers and increase cooperation among its members

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