The Collaborative International Dictionary of English v.0.48:
Austronesia \Austronesia\ n. 1. the area comprising the islands of central and S Pacific (Indonesia and Melanesia and Micronesia and Polynesia). [WordNet 1.5]WordNet (r) 3.0 (2006):
Austronesia n 1: islands of central and South Pacific (Indonesia and Melanesia and Micronesia and Polynesia)