nationalismEnglishOxford American Thesaurusnationalism noun 1 granting greater autonomy to Scotland is awakening English nationalism: separatism, secessionism, partitionism, isolationism; sectarianism. ▷antonyms unionism, federalism. 2 the resurgence of nationalism in Europe and in other parts of the world: chauvinism, jingoism, flag-waving; ethnocentrism, ethnocentricity.