Arzareth:

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).