Boyd’s Bible Dictionary:

(descender). Chief river of Palestine, rising in the Anti-Libanus range, flowing southward, enlarging into Sea of Galilee, emptying into Dead Sea. A swift, narrow, yet fordable stream, with an entire course of about 200 miles (Gen. 13:10; Josh. 2:7; Judg. 3:28; 2 Sam. 10:17; Matt. 3:13).

Concise Bible Dictionary:

The Jordan River in Spring
The river of Palestine is first referred to when Lot chose the plain of Jordan, because it was well watered, as the garden of the Lord (Gen. 13:10). The first great event at the river was when the waters from above were driven back, and those below failed and were cut off, and Israel marched over on dry land. They had previously passed through the Red Sea, but the details of the two passages are quite different. At the Red Sea Moses lifted up his rod and the waters divided; but at the Jordan it was when the feet of the priests bearing the ark were dipped in the water that it divided. The ark also remained in the river until all had passed over. Twelve stones were taken out of the river to form a cairn on the land, and twelve stones were placed in the bed of the river to be covered by the water. The waters were piled up at Adam, some twenty miles from where the Israelites crossed; but at the Red Sea the water was as a wall on each side (Josh. 3:8-17; Josh. 4:1-24). (The waters being piled up “at Adam” [Josh. 3:16] is according to the Hebrew text [see also RV and Mr. Darby’s Trans.]; the reading “from Adam” is according to the Keri.)
All this was typical: the passage of the Red Sea typified Christ dying for the believer (by which the believer escapes death and judgment); the passage of the Jordan typified the believer dying with Christ, and being raised with Him (the path of death becomes the path of life), according to Colossians 2:20 and Colossians 3:1. The waters of the river overflowing its banks at that time typified that the full power of death was met, and overcome by the death and resurrection of Christ. The Jordan, itself has often been taken as a type of death having to be passed in order to enter heaven; but it is rather a figure of the entrance, while on earth, through death with Christ to the heavenly position of the Christian, where he has to stand for the Lord in conflict with spiritual powers of wickedness (compare Eph. 6:10-18), as Israel had to fight the Canaanites, and so make good the Lord’s possession through them of the promised land.
The Jordan River – (a possible baptism site)
The Jordan may further be regarded as the boundary of the promised land, so that the two and a half tribes who stayed on the east of the Jordan stopped short of their privileges. They are a type of many Christians who do not in faith accept the heavenly portion, through death and resurrection, that God intends for them. They are thus more exposed to the attacks of the enemy, as were the two and a half tribes who were the first to be carried into captivity.
The Jordan River—Galilee
The SWELLING OF JORDAN is alluded to as causing dangers or difficulties. It not only prevented persons crossing at the usual fords, but it disturbed the wild beasts in their lairs on its banks, as is three times alluded to (Jer. 12:5; Jer. 49:19; Jer. 50:44). Various incidents and conflicts occurred at the river or on its banks which do not call for remark. In the New Testament it was where John baptized.
The Jordan is like no other river in the world. The Hebrew name for it, Yarden, always has the article, and signifies “the Descender.” It is remarkable for the great fall it has from its source to the Dead Sea. It may be said to have three sources: the highest near Hasbeiya, between Hermon and Lebanon, some 1700 feet above the level of the sea; the second, near the ruins of Banias, the ancient Caesarea-Philippi; and the third near Tell el Kady, the ancient Dan. The three streams unite with other smaller ones and enter a large morass issuing in the lake of Huleh, which is also called “the waters of Merom.” This is estimated to be seven feet above the level of the sea. The Jordan issues from the lake in a stream about a hundred feet wide, running south. About two miles from the lake is a bridge called Jisr Benat Yakub, “Bridge of Jacob’s Daughters,” where Jacob is supposed to have crossed. Its banks from this point contract, and the stream rushes violently down a rocky bed, but gets more gentle before it reaches the Lake of Gennesaret. The distance from lake to lake is about ten miles, but the windings of the river make its length about thirteen miles. The Lake of Gennesaret is 682 feet below the level of the sea, giving a fall of 689 feet in the thirteen miles.
The river leaves this lake about a hundred feet wide and soon passes the remains of a Roman bridge. Some six miles from the lake is a bridge called Jisr el Mujamia. The river here is deep and rapid; but about fifteen miles farther south an island divides the river and there it is often fordable, as it is also near Jericho, and at low water in many other places. Another bridge is called Jisr ed Damieh, about 32° 6' N. The river’s greatest width is mentioned as 180 yards and it is about three feet deep on entering the Dead Sea. This is 1292 feet below the level of the sea, being 610 below the Lake of Gennesaret; the distance is about 65 miles, but the water-way has been estimated to be as much as 200 miles: during its course it has 27 rapids. There are several streams that run into the Jordan both on the east and the west. The two principal ones are on the east: the Yarmuk or Wady Hieromax and the Jabbok, now called Wady Zerka. They are both at times called rivers.
The valley in which the Jordan runs is called the Ghor. On the east it is bounded by a high table land and on the west by high hills. In the valley is a terrace of vegetation, and in the middle of this are the true banks of the river, having in places a jungle of willows, reeds, canes, and such like. See SALT SEA.

Strong’s Dictionary of Hebrew Words:

from 3381; a descender; Jarden, the principal river of Palestine
KJV Usage:

Jackson’s Dictionary of Scripture Proper Names:

their descent

Potts’ Bible Proper Names:

Constant sounding; descending:―chief river of Palestine [JARED], Josh. 2:7. {Continuus strepitus}