Ó hIarnáin
Ó hIARNÁIN—I—O Hiernan, O Hernane, Hearnon, Hernon; 'descendant of Iarnán'; the same as Ó hEarnáin, which see; the name (1) of a family of Ui Fiachrach, in Co. Mayo, and (2) of a family of Corca Laoighdhe, in south-west Cork.
Alphabetical Index to Irish Surnames