Easton's Bible Dictionary (1897)
The valley, now quite narrow, between the Mount of Olives and Mount Moriah. The upper part of it is called the Valley of Jehoshaphat. ” The word means “black,” and may refer to the colour of the water or the gloom of the ravine, or the black green of the cedars which grew there. John 18:1, “Cedron,” only here in New Testament.
Smith's Bible Dictionary (1863)
properly Kidron.
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
KE'DRON, or KID'RON (black brook, from a Hebrew root signifying "black," not from cedars, cedar-brook), is a small stream dry in summer, but growing into a torrent in the rainy season; rises 1 1/2 miles north-west of Jerusalem; runs in a south-eastern direction; strikes the north-eastern corner of the wall of the city; sweeps through the valley of Jehoshaphat in a deep gorge along the eastern side of the city, whose wall rises 100 feet above its bottom, while on the other side the peak of Mount Olivet rises about 500 feet; breaks through a still narrower cleft between the Hill of Offence and Moriah, and continues its course through a wild and dismal channel through the wilderness of Judah, passing by the curious convent of Mar Saba, until it reaches the north-western shore of the Dead Sea.
Its name perhaps refers to the gloom of the valley, or perhaps to the peculiar nature of impurity connected with it. 2 Chr 29:16: 2 Chr 30:14; 2 Kgs 23:4, 2 Kgs 23:6, 2 Kgs 23:12. In the time of Josiah it became the common burial-place of the city, 2 Kgs 23:16, and so it is to-day. The two events, however, connected with it, and which give it its greatest interest, are David's crossing it on his flight from Jerusalem when Absalom rebelled, 2 Sam 15:23, 2 Sam 15:30, and Christ's crossing it on his way to Gethsemane. John 18:1; Mark 14:26; Luke 22:39.
As Caesar crossed the Rubicon for the military conquest of the world, so Christ crossed the Kedron for the salvation of the world.