Livre is a unit of measurement used to denote weight, primarily in France and some other countries. It is equivalent to approximately 0.5 kilograms or 500 grams. The term is derived from the Latin word "libra," which means balance or scale. In addition to its use as a weight measurement, livre also refers to a historical currency in France, known as the livre tournois. This currency was used before the introduction of the franc and was subdivided into smaller units called deniers and sous.