What is "tyras"

Tyras was an ancient Greek city on the northern coast of the Black Sea. It was founded by colonists from Miletus, probably about 600 BC. The city was situated some 10 km from the mouth of the Tyras River, which is now called the Dniester. The surrounding native tribe was called the Tyragetae. The ruins of Tyras are now located in the modern city of Bilhorod-Dnistrovskyi in the Odessa Oblast of Ukraine.