Ó Beannacháin
Ó BEANNACHÁIN—I—O Benachain, O Benachane, O Benahan, Banahan; 'descendant of Beannachán' (diminutive of beannach, pointed, peaked, horned); the name of an old Sligo family who, according to O'Flaherty, are of Firbolgic descent.
Alphabetical Index to Irish Surnames