Styx
Webster's Dictionary [1]
(n.) The principal river of the lower world, which had to be crossed in passing to the regions of the dead.
Cyclopedia of Biblical, Theological and Ecclesiastical Literature [2]
in Grecian mythology, the dark river of the nether world in whose name the gods uttered their irrevocable vows. Styx is described as a daughter of Oceanus and Tethys, and as married to the Titan Pallas, by whom she became the mother of Zelus, Nice, Cratus, Bia and others. With her children she dwelt in a magnificent palace in Tartarus, which rested on silver columns and had its roof of stone raised up until it almost touched the heavens. By Zeus she became the mother of Persephone (Apollod. 1, 3, 1), and by Peiras of Echidna (Pausan. 8, 16, 1). Although a goddess, Styx appears to have been excluded from the society of the gods.
The Nuttall Encyclopedia [3]
Name (from the Greek verb signifying "to abhor") of the principal river of the nether world, which it flows sluggishly round seven times; is properly the river of death, which all must cross to enter the unseen world, and of which, in the Greek mythology, Charon was the ferryman. In their solemn engagements it was by this river the gods took oath to signify that they would forego their godhood if they swore falsely. The Styx was a branch of the Great Ocean which girds the universe. See Oceanus .
