Learn how to say Melanesians correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word Melanesia:
a region of the western Pacific to the south of Micronesia and west of Polynesia. It contains the Bismarck Archipelago, the Solomon Islands, Vanuatu, New Caledonia, Fiji, and the intervening islands.
from Greek melas ‘black’ + nēsos ‘island’