De Cliofort
de CLIOFORT—XI—de Clifford, Clifford; Norman 'de Clifford,' i.e., of Clifford, a parish in Herefordshire. The name is old in Ireland, but the vast majority of our Cliffords are of Irish origin. See Ó Clúmháin and Ó Colmáin.
Alphabetical Index to Irish Surnames