noun Classical Mythology.
Examples from the Web for styx
Fallon wasn't too shabby himself, performing admirable renditions of Iggy Azalea's "Fancy" and Styx's "Mr. Roboto."Viral Video of the Day: Emma Stone's Lip Sync Battle|The Daily Beast Video|April 29, 2014|DAILY BEAST
This great strange goddess had sworn never to love or marry—had sworn it by Styx, I suppose.Gods and Heroes|R. E. Francillon
God, in truth, knows no other judge that can compel him to give what may turn to evil, he is not like Jupiter who fears the Styx.Theodicy|G. W. Leibniz
To-morrow, was it not, that you were to journey to Tyburn and from thence across the Styx?A Daughter of Raasay|William MacLeod Raine