Added 9 October 2026 byzantium noun Categories: PlacesRare Words noun ! Definition from WordNet 3.1, Princeton University. More about byzantium at Wordnik → Where our words come from → An ancient city on the Bosporus founded by the Greeks; site of modern Istanbul; in 330 Constantine I rebuilt the city and called it Constantinople and made it his capital. A continuation of the Roman Empire in the Middle East after its division in 395. Related Words: istanbulconstantinopletsargradstamboulrhomaniabyzantionmiklagardkonstantinoupolispolisbizantiumconstantinopolis Back to today's word