Mafioso Syllabification: (Ma·fi·o·so)Pronunciation: /ˌmäfēˈōsō, -zō/ (also mafioso)Definition of Mafioso noun (plural Mafiosi /-sē, -zē/) a member of the Mafia. Origin:ItalianMafioso in other Oxford dictionaries Definition of Mafioso in the British & World English dictionary