🔼The name Arnon in the Bible
The name Arnon belongs to a river that marked the border between Moab and the territory of the Amorites (Numbers 21:13). When Israel battles the Amorites they conquer them and take their land from the Arnon to the Jabbok (Numbers 21:24).
Much later the prophet Jeremiah cries out, "Wail and cry out, declare by the Arnon that Moab has been destroyed" (Jeremiah 48:20).
Our name is mostly spelled ארנון, but sometimes as ארנן (for instance in Numbers 21:24-28, 22:36, Deuteronomy 2:24, 2 Kings 10:33).
🔼Etymology of the name Arnon
It's not clear where the name Arnon comes from but a Hebrew audience would have readily made the connection with either the noun ארן or the verb רנן:
Neither BDB Theological Dictionary nor NOBSE Study Bible Name List translates this name, but for a meaning of the name Arnon Jones' Dictionary of Old Testament Proper Names goes with the verb רנן and reads Murmuring or Roaring, "i.e. a sounding torrent".