1Greek MythologyA goddess of the sea, daughter of Uranus (Heaven) and Gaia (Earth).
2AstronomyA satellite of Saturn, the ninth closest to the planet and probably composed mainly of ice, discovered by Cassini in 1684 (diameter 1,050 km).
3GeologyAn ocean formerly separating the supercontinents of Gondwana and Laurasia, the forerunner of the present-day Mediterranean.