De Grannt
de GRANNT—XII—de Graunt, Grant; Norman 'le Graunt,' 'le Grant,' i.e., the great, gigantic in size; the name of a Norman family who came to Ireland some time before the end of the 13th century and settled in Kilkenny, Tipperary, Waterford and Cork. The Grants were also a Scottish clan, some of whom settled in Ulster at the time of the plantation, and are still represented in that province.
Alphabetical Index to Irish Surnames