Ó Gréacháin
Ó GRÉACHÁIN—I—O Greghane, O Greaghan, O Grahin, O Gryhen, O Gryhme, O Grame, Greaghan, Greahan, Grehan, Gregan, Greyhan, Grayhan, Greaham, Greham, Graham, Greame, Graeme, Grame, Greames, Grimes; 'descendant of Créachán' (diminutive of créach, blind); a variant of Ó Créacháin (which see) owing to the softening of the initial C to G. It is undoubtedly the name which has been corrupted to Ó Greidhm (which see) in Munster.
Alphabetical Index to Irish Surnames