Lactose is a disaccharide. It is a sugar composed of galactose and glucose and has the formula C12H22O11. Lactose makes up around 2–8% of milk (by weight). The name comes from lac (gen. lactis), the Latin word for milk, plus the suffix -ose used to name sugars. The compound is a white, water-soluble, non-hygroscopic solid with a mildly sweet taste. It is used in the food industry.
To secrete or produce milk
Any salt or ester of lactic acid
The disaccharide sugar of milk and dairy products, C12H22O11, a product of glucose and galactose used as a food and in medicinal compounds.