Mac Giolla Mhearnóg
Mac GIOLLA MHEARNÓG—IV—M'Gillavearnoge, Warnock; 'son of Giolla Mhearnóg' (servant of St. Mearnog); an old Co. Down surname, now shortened to Mac Mhearnóg, which see; also in use in Scotland, where it is Englished Graham.
Alphabetical Index to Irish Surnames