Wordnet 3.0
NOUN (1)
1. 
 a large group of islands in the south Pacific including Melanesia and Micronesia and Polynesia (and sometimes Australasia and the Malay Archipelago); 
[syn: Oceania, Oceanica]
The Collaborative International Dictionary of English v.0.48:
Oceanica \Oceanica\ prop. n.
   Same as Oceania.
   [WordNet 1.5]
WordNet (r) 3.0 (2006):
Oceanica
    n 1: a large group of islands in the south Pacific including
         Melanesia and Micronesia and Polynesia (and sometimes
         Australasia and the Malay Archipelago) [syn: Oceania,
         Oceanica]