internationalism Syllabification: (in·ter·na·tion·al·ism)Pronunciation: /ˌintərˈnaSHənlˌizəm/Definition of internationalism noun 1the state or process of being international:the internationalism of popular music the advocacy of cooperation and understanding between nations. 2 (Internationalism) the principles of any of the four Internationals. Derivatives internationalist noun internationalism in other Oxford dictionaries Definition of internationalism in the British & World English dictionary