Cyanean

Cyanean is an adjective and historic toponym used in classical geography to refer to things connected with the Cyanean Rocks, a pair of notable rock outcrops in the Black Sea that ancient navigators cited as a landmark at the approach to the straits leading to the Sea of Marmara. In later sources these rocks are sometimes called the Chelidonian Rocks. The name is generally linked to the Greek origin kyaneos, meaning blue, reflecting a likely reference to the color of the water around the rocks or the sea itself.

In antiquity, Cyanean and its related forms were used to describe the rocks and, more broadly, the maritime zone surrounding them. The term appeared in geographical and navigational writings as a way to mark the boundary between different seas or shores and to signal hazards to sailors working the Black Sea trade routes. The Cyanean Rocks thus functioned as a landmark of classical seamanship and regional geography.

In modern reference works, Cyanean is encountered mainly in historical, geographical, and textual contexts. It serves as a literary and scholarly toponym rather than a current geographical designation, and is often discussed in studies of ancient navigation, cartography, and Greek nomenclature. The term persists in encyclopedic and dictionary entries as part of the nomenclature surrounding the Cyanean Rocks and related ancient geography.