Lethe: The River of Forgetfulness in Greek Mythology In the underworld of Greek mythology, Lethe is not a river of punishment or torment, but of forgetting. Its name comes from the Greek word lḗthē, meaning oblivion or concealment. To drink from its waters is to lose memory—not only of pain and sorrow, but of identity itself. Lethe flows through the realm of Hades, alongside other rivers of the dead such as Styx, Acheron, Cocytus, and Phlegethon. Yet while those rivers are associated with oaths,