dolphin [LME] The name for this small whale goes back through French and Latin to Greek delphin. The form delphin existed in English from the early Middle Ages, but dolphin, from its French equivalent, appeared in the later Middle Ages and finally ousted the earlier word during the 17th century. In another guise the French word entered English as dauphin, the eldest son of the King of France. This is from the family name of the lords of the Dauphiné, an area of south-east France. In 1349 the future Charles V acquired the lands and title of the Dauphiné, with a condition that Dauphin should become the title of the king’s eldest son. A heraldic dolphin was part of their coat of arms.