Medeba

waters of quiet, an ancient Moabite town (Num 21:30). It was assigned to the tribe of Reuben (Josh 13:16). Here was fought the great battle in which Joab defeated the Ammonites and their allies [(1Chr 19:7-15); comp. (2Sam 10:6-14)]. In the time of Isaiah (Isa 15:2) the Moabites regained possession of it from the Ammonites. (See HANUN)

The ruins of this important city, now Madeba or Madiyabah, are seen about 8 miles south-west of Heshbon, and 14 east of the Dead Sea. Among these are the ruins of what must have been a large temple, and of three cisterns of considerable extent, which are now dry. These cisterns may have originated the name Medeba, "waters of quiet." (See OMRI)

EBD - Easton's Bible Dictionary