Lynch, ó Loingsigh, de Leach
A Gaelic surname meaning descendant of Loingseach, which personal name meant ‘seafarer, exile’. A sept who were Chiefs of Dál Riada (Antrim and Down), they were dispossessed at the time of the Cambro-Norman invasion. A sept of Owney who were Chiefs of Uaithne Thíre, now the barony of Owney in Tipperary. Sometime after the Cambro-Norman invasion they were dispossessed by the ó Maolriain. A sept of Breifne, who were Chiefs of Cineál Bhacaid. A sept of the Dál gCais in Thuas Mhumhan (Thomond). A sept of the Corcu Lóighdhe, who were originally seated in west Cork. A sept of the Uí Fiachrach, who were settled in Sligo. A sept of Meath. Also de Lench of Cambro-Norman origin one of the ‘Tribes of Galway’. In 1890 Lynch was the seventeenth most numerous name in Ireland, the estimated number of bearers was 19,800, and it was the most numerous surname in Westmeath The surname was to be found in nearly every county in Ireland and it was chiefly to be found in Cork, Cavan, Dublin, Kerry, Limerick, Clare, Meath and Derry. In the United States Lynch is the 235th most numerous surname with an estimated 123,750 bearers. It is numerous in the states of Connecticut, Delaware, and New Jersey. In England and Wales in 1996 it was the 249th most numerous surname.