Bible Meaning: Rushing (brawling) stream
Strong's Concordance #H769
The Arnon River, which flows into the Dead Sea on its eastern side, was once the dividing line between territory controlled by the Moabites and Amorites.
The children of Israel, under Moses' leadership, conquer the Amorites in late 1406 B.C. The land north of the Arnon is ultimately given to the tribes of Reuben and Gad (Deuteronomy 3:16, Joshua 13).
Later the Ammonites (not to be confused with the Amorites) try to take the land north of the Arnon for themselves. Israel, under the leadership of Jephthah, defeats them in battle (Judges 11:12 - 33).
Numbers 21:13, 26
From thence they removed, and pitched on the other side of Arnon, which is in the wilderness that cometh out of the coasts of the Amorites: for Arnon is the border of Moab, between Moab and the Amorites.
For Heshbon was the city of Sihon the king of the Amorites, who had fought against the former king of Moab, and taken all his land out of his hand, even unto Arnon.
And when Balak heard that Balaam was come, he went out to meet him unto a city of Moab, which is in the border of Arnon, which is in the utmost coast.
Rise ye up, take your journey, and pass over the river Arnon: behold, I have given into thine hand Sihon the Amorite, king of Heshbon, and his land: begin to possess it, and contend with him in battle.
And this land, which we possessed at that time, from Aroer, which is by the river Arnon, and half mount Gilead, and the cities thereof, gave I unto the Reubenites and to the Gadites.
Now these are the kings of the land, which the children of Israel smote, and possessed their land on the other side Jordan toward the rising of the sun, from the river Arnon unto mount Hermon, and all the plain on the east:
And the king of the children of Ammon answered unto the messengers of Jephthah, Because Israel took away my land, when they came up out of Egypt, from Arnon even unto Jabbok, and unto Jordan: now therefore restore those lands again peaceably.
From Jordan eastward, all the land of Gilead, the Gadites, and the Reubenites, and the Manassites, from Aroer, which is by the river Arnon, even Gilead and Bashan.
For it shall be, that, as a wandering bird cast out of the nest, so the daughters of Moab shall be at the fords of Arnon.
Moab is confounded: for it is broken down: howl and cry: tell ye it in Arnon, that Moab is spoiled