A female name. (Latin Teresia, Theresia, Spanish, Italian Teresa, German Theresa, Theresia, French Thérèse). The origin of this name is obscure, and there is no real evidence for the usually accepted etymology from Greek θερίζω ‘to reap’. Θηρασία was the name of an island near Crete and of another near Sicily, and there may be some connexion between this and the personal name. It is first found as Therasia, the name of the wife of St Paulinus, Bishop of Nola in the 5th C, who was converted by her. She was a Spaniard, and the name was for many centuries confined to the Iberian peninsula. There was a queen of Leon of this name in the 10th C, and it was firmly established in the royal house of Castile in the 11thC. It did not spread outside the Iberian peninsula until the 16th C, when the fame of St Teresa of Avila (1515-82) carried it into all Roman Catholic countries. In recent times the popularity of the name in such countries has been increased by St Thérèse of Lisieux (1873-97). It was not much used in England until the 18th C, when it was introduced by the admirers of the Empress Maria Theresia of Austria. It is now chiefly used in the abbreviated form Tess or Tessa.

Described by Helena Swan as ‘the Italian and Spanish form of Theresa’, it is now the usual form of a f. which, in its Greek original, indicates ‘a reaper’ (lit. ‘carrying ears of corn’) and the bad old days when, as still on the Continent, women worked in the fields. It leapt into popularity simultaneously with the spreading of the fame of St. Teresa, who reformed the Carmelite Order, wrote significantly on the nature, procedure and value of mystical prayer, founded over thirty convents, died in 1582, and left an autobiography ‘written with charming candour, and, from the literary point of view, a Spanish classic’ (Benedictines).