Ó Luingeacháin
Ó LUINGEACHÁIN—I—O Lunyghan, Lunican, Lonican, Linighan, Linahan, Linehan, Lenihan, &c.; 'descendant of Longachán' (diminutive of Longach); an attenuated form of Ó Longacháin, and apparently a substitution for the old East Limerick or Tipperary surname Mac Longacháin; common in Cork, Limerick and Kerry.
Alphabetical Index to Irish Surnames