Lethe

Cyclopedia of Biblical, Theological and Ecclesiastical Literature

(λήθη, oblivion), in the Grecian mythology, the stream of forgetfulness in the lower world, to which the departed spirits go, before passing into the Elysian fields, to be cleansed from all recollection of earthly sorrows. (See Hades).

The Nuttall Encyclopedia

E . oblivion), in the Greek mythology a stream in the nether world, a draught of the waters of which, generally extended to the ghosts of the dead on their entrance into Pluto's kingdom, obliterated all recollection of the past and its sorrows.