international organization vs world organisation

international organization and world organisation both are nouns.

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

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

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

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

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