fleur·de·lys | ˌflər-də-ˈlē
noun
A stylized, three-petaled iris flower used as the armorial emblem of the Kings of France and then re-popularized by Napoleon
Fler-de-lis is derives from old French "Flor de lis": Flor (flower) + de (of) + lis (lily). It is an element commonly found in jewelry.