Istanbul
WordNet
noun
(1) The largest city and former capital of Turkey; rebuilt on the site of ancient Byzantium by Constantine I in the fourth century; renamed Constantinople by Constantine who made it the capital of the Byzantine Empire; now the seat of the Eastern Orthodox Church
WiktionaryText
Etymology
The name Istanbul was given to the city of Constantinople after the Turkish War of Independence in 1453.
The word is a bastardization of the Byzantine Greek phrase , which is how Constantinople was referred to by the local Greeks. The Turks sometimes ascribe the etymology of Istanbul to the phrase Islam bol (“plenty of Islam” or possibly “city of Islam”), as the Byzantine Greek word for city has been adopted into Turkish as .