From the equivalent of edra'; mighty; Edrei, the name of two places in Palestine -- Edrei.
see HEBREW edra'
H154. Edrei
אֶדְרֶ֫עִי proper name, of a location a chief city of Bashan אֶדְרֶ֖עִי Joshua 19:37; אֶדְרֶ֑עִי Numbers 21:33 = Deuteronomy 3:1, 10; בְּאֶדְרֶ֑עִי בְּעַשְׁתָּרֹת 1:4; וּבְאֶדְרֶ֑עִי בְּעַשְׁתָּרֹת Joshua 12:4; 13:12; compare 13:31; — on identity of all these compare Di Deuteronomy 3:10; modern Der`ât, 7 2-Janhours west-northwest of Bosra; Euseb. Ἀδραά (LagOnom. 213, 86 2nd ed. 235) compare Di Numbers 21:33 WetzstHauran 47, 77, 123 BdPal 201.