mannitolPronunciation: /ˈmanɪtɒl/Definition of mannitol noun [mass noun] Chemistry a colourless sweet-tasting crystalline alcohol which is found in many plants and is used in various foods and medical products. Chemical formula: CH2OH(CHOH)4CH2OH Origin: late 19th century: from mannite (from manna + -ite1), in the same sense, + -olmannitol in other Oxford dictionaries Definition of mannitol in the US English dictionary