Mac Giolla tSeanáin
Mac GIOLLA tSEANÁIN—IV—Giltenane, Giltinane, Giltenan, Shannon; a variant of Mac Giolla Seanáin, which see. This form of the name is in use in Co. Clare, where it is corrupted to Ó Cilltreáin and often anglicised Shannon.
Alphabetical Index to Irish Surnames