Ó Toráin
Ó TORÁIN—I—O Tarrane, O Tarran, O Turran, Toran, Torran, Thoran, Thorn, Tarrant, Torrans, Torrens, Torrins, Torrance, Torrence, (Thornton), &c.; 'descendant of Torán' (diminutive of tor, a lord); also written Ó Taráin; originally a Derry surname apparently; now rare and scattered.
Alphabetical Index to Irish Surnames