A seaport of Turkey in Asia, situated on a narrow isthmus connecting with the mainland the rocky headland of Cape Sinope which projects into the Black Sea, 350 m. NE. of Constantinople; possesses two fine harbours, naval arsenal, Byzantine ruins, etc.; an ancient Greek town, the birthplace of Diogenes, and capital of Mithridates; it was captured by the Turks in 1461, who themselves in 1853 suffered a disastrous naval defeat in the Bay of Sinope at the hands of the Russians.