Aroer - (Easton's Bible Dictionary)
Ruins. (1.) A town on the north bank of the Arnon (Deut. 4:48; Judg. 11:26; 2 Kings 10:33), the southern boundary of the kingdom of Sihon (Josh. 12:2). It is now called Arair, 13 miles west of the Dead Sea.
(2.) One of the towns built by the tribe of Gad (Num. 32:34) "before Rabbah" (Josh. 13:25), the Ammonite capital. It was famous in the history of Jephthah (Judg. 11:33) and of David (2 Sam. 24:5). (Comp. Isa. 17:2; 2 Kings 15:29.)
(3.) A city in the south of Judah, 12 miles south-east of Beersheba, to which David sent presents after recovering the spoil from the Amalekites at Ziklag (1 Sam. 30:26, 28). It was the native city of two of David's warriors (1 Chr. 11:44). It is now called Ar'arah.