De Suingean
de SUINGEAN—XI—de St. John, St. John, Singen, Singin, etc., Norman 'de St. Jean'; Latin 'de Sancto Johanne,' i.e., of St. Jean, a common French place-name. This family settled early in Wexford, Kilkenny and Tipperary. Thomas de St. John was sheriff in Tipperary in 1296.
Alphabetical Index to Irish Surnames