international organization vs world organization

international organization and world organization both are nouns.

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

As nouns, international organization and world organization are synonyms defined as:

international organization and world organization: an international alliance involving many different countries

Other synonyms of international organization include global organization, international organisation, world organisation.

international organization (noun)	world organization (noun)
an international alliance involving many different countries	an international alliance involving many different countries