Definition of Istanbul
- a port in Turkey on the Bosporus that straddles Europe and Asia; population 10,757,300 (est. 2007). Formerly the Roman city of Constantinople 330–1453, it was built on the site of the ancient Greek city of Byzantium. It was captured by the Ottoman Turks in 1453 and was the capital of Turkey from that time until 1923.
Turkish, from Greek eis tēn polin 'into the city'