Siúrdán
SIÚRDÁN, SIÚRTÁN—VIII—Jurdane, Jordane, Jurdan, Jordan, &c.; 'son of Jordan' (a personal name derived from the river Jordan, which became popular in crusading times throughout Western Europe, and nowhere more than in England, owing to flasks of Jordan water being brought home to be used for baptismal purposes). The Jordans were an Anglo-Norman family who settled early in Dublin, Meath, Limerick, &c. Jordan of Hilton was one of the chief gentlemen of Dublin at the end of the 16th century, and at the same period three of the name were mayors of Limerick. This surname is to be distinguished from Mac Shiúrtáin, which see.
Alphabetical Index to Irish Surnames