the islands in the southwestern part of Oceania

Melanesia (from Greek: μέλας black, νῆσος island) is a region extending from the western side of the East Pacific to the Arafura Sea, north and north-east of Australia. The term was first used by Jules Dumont d'Urville in 1832 to denote an ethnic and geographical grouping of islands distinct from Polynesia and Micronesia.