De Sionúir
de SIONÚIR—XI—de Synors, de Sinors, de Sunors, Shinnor, Shinnors; Norman 'de Sinors,' etc., i.e., of Sinors or Sunors, apparently some spot in England; an old, but rare, Anglo-Norman surname found chiefly in East Limerick and in parts of Connacht. See Sionúir.
Alphabetical Index to Irish Surnames