Ó Duirnín
Ó DUIRNÍN—I—O Durnyne, O'Durnin, Durnin, Durnian, Durnion, Dornin, and, by 'translation,' Cuffe; 'descendant of Duirnín' (diminutive of dorn, a fist); an Ulster surname. In the 16th century it was found chiefly in Donegal, and Fermanagh. See Ó Dornáin.
Alphabetical Index to Irish Surnames