Ushant (ŭshˈənt) [key], Fr. Ouessant, island, 10 sq mi (25.9 sq km), Finistère dept., off Brittany, in the Atlantic, c.10 mi (16 km) from the mainland. A hazard to navigation and subject to intense fall and winter storms, Ushant has several lighthouses and marks the southwestern entrance to the English Channel. Sheep raising and fishing are economically important, as is summer tourism. In 1778 and 1794 naval battles occurred nearby between the French and English.