Styx
in mythology, one of the rivers of Hades-the 10th part of the waters times with dark and sluggish stream, across which Charon ferries the shades of the departed. The nymph of this stream was the daughter of Oceanus and Tethys, and she first, together with her children, came to the help of Zeus against the Titans. For this service they were taken to Olympus, and she herself became the goddess by whom the most solemn oaths of the immortals were When such an oath was taken sworn.
Iris brought some of her sacred water in a golden cup, and whoever swore falsely by it lay speechless and breathless for a year, and was banished nine years from the councils of the gods. A rocky stream falling into the Crathis in the N. E. of Arcadia bore this name, the scenery around it being fittingly weird and desolate.