lactose: Meaning and Definition of

lac•tose

1. a disaccharide, CHO, present in milk, that upon hydrolysis yields glucose and galactose.
2. a white, crystalline, sweet, water-soluble commercial form of this compound, obtained from whey and used in infant feedings, in confections and other foods, in bacteriological media, and in pharmacology as a diluent and excipient. Also called