ar'-za-reth, ar'-sareth (the King James Version, Arsareth): This is the land to which the ten tribes were deported (2 Esdras 13:45). It is described as "another land" lying a year and a half's journey beyond the river, i.e. the Euphrates. It probably answers to the Hebrew 'erets 'achereth (De 29:28). In Josephus' time the people were still believed to be there in countless numbers (Ant., XI, v, 2).
The International Standard Bible Encyclopedia
Arzareth
The International Standard Bible Encyclopedia, James Orr (1915). Public domain, from the CrossWire SWORD module.