EEC vs EU

EEC and EU both are nouns.

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

As nouns, EEC and EU are synonyms defined as:

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

EEC (noun)	EU (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