Nusantara noun4 •A region of Southeast Asia: generally used to refer to Maritime Southeast Asia, which includes Indonesia, Malaysia, Singapore, Brunei, and the Philippines. •The planned capital city of Indonesia in East Kalimantan, on Borneo.The de jure capital city of Indonesia is Nusantara, located in the eastern coast of Kalimantan island. •(historical) A region of Southeast Asia. The conquered territories of the Majapahit empire, corresponding to present-day Indonesia (main) and several Southeast Asian countries. •A country in Southeast Asia: Endonym for the Republic of Indonesia, including everything contained within it (i.e., covering the regions, people, cultures, languages, etc.).