Oceania Syllabification: (O·ce·an·i·a)Pronunciation: /ˌōSHēˈanēə, -ˈänēə/Definition of Oceania an area that encompasses the islands of the Pacific Ocean and adjacent seas. Derivatives Oceanian adjective & noun Origin:modern Latin, from French OcéanieOceania in other Oxford dictionaries Definition of Oceania in the British & World English dictionary