Oxford Dictionary English national costume nounnoun BrE BrE//ˌnæʃnəl ˈkɒstjuːm// ; NAmE NAmE//ˌnæʃnəl ˈkɑːstuːm// [countable, uncountable] (also national dress [uncountable]) Add to my wordlistjump to other resultsthe clothes traditionally worn by people from a particular country, especially on special occasions or for formal ceremoniesSee national costume in the Oxford Advanced American DictionaryCheck pronunciation: national costume oxfordlearnersdictionaries.com