a sugar comprising one glucose molecule linked to a galactose molecule; occurs only in milk
Cow's milk contains about 4.7% lactose.
source: WordNet 3.0
Sugar of milk or milk sugar; a crystalline sugar present in milk, and separable from the whey by evaporation and crystallization. It has a slightly sweet taste, is dextrorotary, and is much less soluble in water than either cane sugar or glucose. Formerly called lactin.
