Ó Loingseacháin
Ó LOINGSEACHÁIN—I—O Lynseghane, Lynchahaun, Lynchahan, Lynchehan, (Lynch); 'descendant of Loingseachán' (diminutive of Loingseach); the name (1) of a family of the Cinel Eoghain in Ulster, who are descended from Loingseach, King of Ireland, and were seated in the present county of Donegal; also called Mac Loingseacháin and Ó Loingsigh, which see; and (2) of a family of the Ui Fiachrach, formerly seated in Co. Sligo. It is now almost always anglicised Lynch.
Alphabetical Index to Irish Surnames