Louis d'or is a type of gold coin that was in circulation in France from the late 17th century to the early 20th century. The French word "d'or" means "of gold," and the coin is named after King Louis XIII of France. Some synonyms for Louis d'or include the French term "ecu," which means "shield," as the coin features a shield on one side. Another synonym is "Louis," as it's short for Louis d'or, and refers to any coin in the series. Additionally, the term "double louis" or "20-franc piece" refers specifically to the Louis d'or coin that was worth 20 French francs.
