by Artur Vrekaj.

According to Demetrius John Georgacas, at the University of Chicago, he writes:

“The name Byzantium is probably Illyrian from Buzas with the suffix -io-; New Rome was an official name (4th century); Constantine polis and ἡ Constantine are not common, while Constantinepolis is the written name and Polis the common name of the world capital. The last name came through ellipsis of Constantine, just as ἡ Constantine by ellipsis of polis. The Turkish name Stambul came from (εἰς τὴν Πόλιν. Details of these names are discussed.”

Reference

Demetrius John Georgacas. “The Names of Constantinople. “Transactions and Proceedings of the American Philological Association.