Chemistry. a white, crystalline, sweetish, water-soluble, carbohydrate alcohol, C6H86, occurring in three optically different forms, the common one being found in the manna of the ash Fraxinus ornus and in other plants: used chiefly in the manufacture of resins, electrolytic condensers for radios, plasticizers, and mannitol hexanitrate, and as a pill excipient.
Pharmacology. the substance used as an osmotic diuretic to reduce intraocular and intracranial pressures.