From the name of a place in Meath, seat of the high kings of Ireland, named with Gaelic teamhair ‘hill’. It has been used as a girl's name in America since the 1940s, probably as a result of the success of the film Gone with the Wind (1939), in which the estate of this name has great emotional significance. In Britain it was not much used before the late 1960s. Its popularity then was influenced by the character Tara King in the television series The Avengers.
French, Spanish, Italian, and English: from a vernacular form of the Latin personal name Vitalis (see Vitale). The English surname may derive, at least in part, as a nickname from the Middle English word vital in the sense ‘full of vitality’.