The synonyms collected by Matheson from returns by local registrars (i.e. forms used indifferently by the same family), in this case Guidera, Guidra and Guider, are a guide to the correct pronunciation of this name, which is neither Guddeera nor Gyder but approximatley Giddera and Gidder. A note by the late Richard Foley (Fiachra Éilgeach)-admittedly not a reliable authority-(Nat. Lib. MS.

G 841) mentions that Aodh de Blacam thought the name to be Mag Fhuadaire (fuadaire rambler) in Irish: I think this most unlikely, but having discovered no Irish form myself I give it for what it is worth.

Foley also states that there is a family of Guidera in Co. Derry and I am informed that they use Mac Giodaire as the Gaelic form of their name. Though this G is slender it does approximate to the correct pronunciation of Guidera but it may only be a modern gaelicization.

So far as my research has gone I have met no early example of the name. The Tipperary hearth money rolls have Daniel Gedery or Gidery (parish of Kilmore) and Donnaigh Gidder (parish of Aghnameadle) both in the barony of Upper Ormond. These are presumably alternative forms of Guider etc.

In the nineteenth century it was fairly numerous in Co. Tipperary, as evidenced by the Tithe Applotment Books (1815-1827) and a generation later by Griffith's Valuation. In almost every case in those records the form given is Guider. It appears to have been then associated particularly with the north of the county around Roscrea, though it also occurs in the south at Clogheen and Clonmel. All the three forms recorded by Matheson as synonyms in 1890, occur in the registrations for 1864 to 1866: only one birth took place outside Co. Tipperary and that was in Dublin, the name there being spelt Guidera.

Mr. P. J. Kennedy informs me that the name in that form is not unknown in east Galway.

This name has long been found in north Tipperary, where it was formerly called Gidery.

Mac Giodaire is the Irish form in use in Co. Derry, where the name is also found. SIF 84