Styx

alternative Stix

1. Greekhuman sciencesThe river, in Hades, over which the souls of the dead are ferried by Charon.

   The Styx was the best-known river in Hades. […] Hades’ house stood on the shore of the Styx.

   1974, C[ovington] Scott Littleton, “Hades”, in The World Book Encyclopedia, volume 9 (H), Chicago, Ill.: Field Enterprises Educational Corporation, →ISBN, page 4, column 2

   3 more examples

   A bold bad man, that dar'd to call by name / Great Gorgon, prince of darknes and dead night, / At which Cocytus quakes and Styx is put to flight.

   1590, Edmund Spenser, “Book I”, in The Faerie Queene. […], London: […] [John Wolfe] for William Ponsonbie, →OCLC, page 13

   For two-and-twenty years he [Doctor Guillotin], unguillotined, shall hear nothing but guillotine, see nothing but guillotine; then dying, shall through long centuries wander, as it were, a disconsolate ghost, on the wrong side of Styx and Lethe; his name like to outlive Cæsar’s.

   1837, Thomas Carlyle, chapter IV, in The French Revolution: A History […], volume I (The Bastille), London: Chapman and Hall, →OCLC, book IV (States-General)

   Bornless one / As darkness bright / Found not in tongues / Found not in light / Bring down the rain / Drain waters of Styx / Faustian luminary / Redeem blaspheme / Like a day without the dawn / Like a ray void of the sun / Like a storm that brings no calm / I'm most complete yet so undone

   2014, “O Father O Satan O Sun!”, performed by Behemoth

2. astronomyThe 5th moon of Pluto, discovered in 2012.
3. A locality in the Derwent Valley council area, south eastern Tasmania, Australia.