The term Fleur-de-lis is a stylized lily or iris flower that is used as a decorative design or symbol. It is commonly associated with the French monarchy and is often used in French heraldry. The crossword solution for the term Fleur-de-lis is LIS, which is an acronym for the Latin phrase 'Lilia Imperii Signum', meaning 'Flower of the Empire'. This phrase was used to describe the Fleur-de-lis symbol during the Middle Ages.