Dalmatia Syllabification: (Dal·ma·tia)Pronunciation: /dalˈmāSH(ē)ə/Definition of Dalmatia an ancient region in what is now southwestern Croatia that is composed of mountains and a narrow coastal plain along the Adriatic Sea, together with offshore islands. It once formed part of the Roman province of Illyricum. Dalmatia in other Oxford dictionaries Definition of Dalmatia in the British & World English dictionary