A coin or unit of account in use in France from the Middle Ages to the 18th century, and divided into 20 sols (or sous).
The livre tournois superseded the livre parisis (equal to 1¼ livres tournois) in the 13th century. From 1360–1641 it was officially equivalent in value to a franc, after which the terms livre tournois and franc were commonly used as synonyms in accounting.
Mid 16th century; earliest use found in John Stubbs (c1541–1590), religious writer. From Middle French livre tournois from livre + tournois of Tours (13th century in Old French as a noun, 1346 as adjective, both earliest with reference to currencies; from post-classical Latin Turonensis of or relating to the region of Tours; from classical Latin Tūrōnēs (also Tūrōnī), the name of the Gaulish people originally inhabiting that region + -ēnsis; compare post-classical Latin Civitas Turonum, the name of Tours, lit. ‘city of the Turones’).