yellowish, semisolid, fragrant essential oil obtained from the roots of the Florentine iris (Iris florentina) and used as a flavouring agent, in perfume, and medicinally. The use of orris oil to flavour candies, soft drinks, and gelatin desserts, once common, has declined owing to components that may cause allergic reactions. Orris oil has mild medicinal properties and was formerly used to treat bronchitis, edema, and liver ailments.