Tadhg · “TYGE ('tiger' without the -er)” · Boy's name · also Teague, Tiege, Timothy, Thaddeus 'poet' or 'philosopher'. So common in Gaelic Ireland that 'Teague' became an English slur for an Irishman — the way 'Paddy' later would. Its real meaning is poet, and it was borne by a son of Brian Boru and by generations of O'Briens and MacCarthys.
Tailtiu · “TAL-tyoo” · Girl's name · also Tailte The name of the goddess who gave Teltown in Meath its name. She is said to have cleared the forests of Ireland for farming and died of the labour, and Lugh founded the Óenach Tailtenn in her memory: the great assembly held at Lughnasadh, with games, law-making and marriages that lasted a year and a day. Teltown in Meath is her.
Tiarnán · “TEER-nawn” · Boy's name · also Tiernan, Tiarnach From tiarna, 'lord' — 'little lord'. Tighearnán Ua Ruairc (Tiernan O'Rourke, king of Bréifne) was the man whose wife Dervorgilla was carried off by Diarmait Mac Murchada in 1152, setting in motion the feud that brought the Normans to Ireland.
Tlachtga · “TLAKHT-ga” · Girl's name · also Tlachta The name of a druidess, and of the Hill of Ward in Meath. Red-haired daughter of the arch-druid Mug Ruith, who travelled the world with her father and learned his secrets. The Hill of Ward in Meath carries her name and was one of the great fire sites of Samhain.
Toirdhealbhach · “TUR-a-lakh” · Boy's name · also Turlough, Terence, Terry 'instigator' or 'shaped like Thor'; disputed. Toirdhealbhach Ua Conchobair, Turlough O'Connor, was king of Connacht and high king with opposition, a great builder of castles and bridges, and the patron who commissioned the Cross of Cong. Turlough O'Carolan, the blind harper, is the name's other giant.
Tomás · “tuh-MAWS” · Boy's name · also Thomas, Tom The Irish form of Thomas. Tomás Ó Criomhthain of the Great Blasket wrote 'An tOileánach' (The Islandman), which ends with one of the most quoted lines in Irish: 'ní bheidh ár leithéidí arís ann' — our likes will not be there again.
Treasa · “TRASS-a” · Girl's name · also Teresa, Toirdhealbhach (m. cognate) Used as the Irish form of Teresa; sometimes read as 'strength'. Adopted widely in the 19th and 20th centuries as the Irish for Teresa, after the Spanish saint — one of many names that entered Irish through devotion rather than descent.
Tuathal · “TOO-hal” · Boy's name · also Toal, Tully 'people-mighty'. Once rather common, now very rare. Tuathal Techtmar is the legendary high king said to have imposed the Boruma tribute on Leinster — the cattle-debt that caused six hundred years of war in the annals.
Tuilelaith · “ta-LOO-la” · Girl's name · also Talulla, Tallulah 'abundance of sovereignty' or 'lady of abundance'. Two abbesses of Kildare bore this name in the 9th and 10th centuries. Its resemblance to the American Tallulah, which comes from a Choctaw place-name, is pure coincidence, but a happy one.