Ó Cúlacháin
Ó CÚLACHÁIN—I—O Coullaghan, O Couloghan, O'Colohan, Cuolohan, Coulihan, &c.; 'descendant of Cúlachán' (diminutive of cúlach, fat); the name of a family of the Ui Fiachrach who were formerly seated in the barony of Carra, Co. Mayo. At the end of the 16th century it was also found in Sligo, Tipperary and Limerick.
Alphabetical Index to Irish Surnames