Mac Ceithearnaigh
Mac CEITHEARNAIGH—IV—M'Kehemie, M'Keherne, Keherny, Kerney, (Kearney); 'son of Ceithearnach'; the name of a Roscommon family who were chiefs of Ciarraidhe, or Kerry, a district in the barony of Castlerea; also Ó Ceithearnaigh (which see), which seems to be the only form in which the name has survived.
Alphabetical Index to Irish Surnames