New Guinea UK [njuː ˈɡɪn.i]US [nu ˈɡɪn.i] noun3 •A large island in the Pacific Ocean north of Australia, in Oceania, whose territory is divided between Indonesia in the west and Papua New Guinea in the east. •(historical) A former dependent territory of Australia, from 1914 to 1975, occupying the northern part of what is now called Papua New Guinea. •(informal) Papua New Guinea: A country in Oceania.