Ó Cumaráin
Ó CUMARÁIN, Ó CUMRÁIN—I—Cameron; 'descendant of *Cumrán'; apparently the same as Ó Cubhráin, which see; the name of an old Breifney family. It is, no doubt, the surname pronounced Cumarán (without the Ó) and anglicised Cameron, in Co. Mayo.
Alphabetical Index to Irish Surnames