Belgia.

Internationalism, based on Latin Belgica and Belgium, from Gallia Belgica (“Belgic Gaul”). Belgica was either formed from belgicus (“Belgic”) or arose as an ellipsis of Gallia Belgica. These names ultimately derive from Belgae, the Roman name for a group of peoples inhabiting northern Gaul. Forms of the ancient name were used more broadly for the Low Countries before being adopted for the modern state when it became independent in 1830. Roman Gallia Belgica did not correspond precisely to the territory of present-day Belgium. One proposal derives the ethnonym Belgae from Proto-Celtic *belgos (“swollen; angry”), perhaps ultimately from Proto-Indo-European *bʰelǵʰ- (“to swell”), but this deeper etymology is uncertain. Compare Danish Belgien, Swedish Belgien, German Belgien, Dutch België, French Belgique and English Belgium.