Styx, << stihks >>, was a gloomy river of the underworld in Greek and Roman mythology. Styx is a Greek word meaning hateful. The boatman Charon was often described as ferrying the souls of the dead across the Styx. The gods took their most sacred oaths by the name of the Styx. If they broke such an oath, they were punished by spending nine years in Tartarus, a deep pit in the underworld. The Styx supposedly began as an actual waterfall in the region of ancient Greece called Arcadia. Its waters, which were said to be poisonous, plunged down a steep gorge to the underworld. See also Elysium; Hades; Tartarus.