Dictionary.com
Thesaurus.com

Styx

American  
[stiks] / stɪks /

noun

Classical Mythology.
  1. a river in the underworld, over which the souls of the dead were ferried by Charon, and by which the gods swore their most solemn oaths.


Styx British  
/ stɪks /

noun

  1. Greek myth a river in Hades across which Charon ferried the souls of the dead

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Styx Cultural  
  1. In classical mythology, one of the rivers of Hades, across which Charon ferried the souls of the dead. The gods occasionally swore by the river Styx. When they did so, their oath was unbreakable.


Etymology

Origin of Styx

from Greek Stux; related to stugein to hate

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Lady Gaga is also teetering around on crutches, cavorting with zombies and crossing the River Styx.

From BBC

“Shame Game” has a psychedelic vibe that’s kinda like a hybrid of Strawberry Alarm Clock and Blue Oyster Cult, while the title track has a prog rock vibe redolent of Styx, Rush and Mars Volta.

From Los Angeles Times

Kentridge likens the captain to the ferryman, Charon, in Greek mythology transporting the dead across the river Styx to the underworld.

From Los Angeles Times

The ancient Greeks could have called the movie “Oh, River Styx.”

From Los Angeles Times

There were tales of heroes' risky voyages along the River Styx, the waterway that connected the human world with the underworld, and of their attempt to thwart Hades, the god of the dead.

From Salon