Oceanica - a large group of islands in the south Pacific including Melanesia and Micronesia and Polynesia (and sometimes Australasia and the Malay Archipelago)Melanesia - the islands in the southwestern part of Oceania Micronesia - the islands in the northwestern part of Oceania Polynesia - the islands in the eastern part of Oceania archipelago - a group of many islands in a large body of water |