international organisation vs world organization

international organisation and world organization both are nouns.

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

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

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

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

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