Fir Teathbha
FIR TEATHBHA, men of Teathbha, or Teffia, the clan-name of the descendants of Maine, son of Niall of the Nine Hostages, who were one of the chief clans of the southern Ui Neill, and whose territory embraced a great portion of Westmeath and also the barony of Kilcoursey in the present Offaly.
Alphabetical Index to Irish Surnames