Common name for any sweet, crystalline, simple carbohydrate which is an aldehyde or ketone derivative of a polyhydric alcohol. Sugars are mainly disaccharides like sucrose and monosaccharides like fructose; all are soluble in dilute alcohol or water and are white in their pure form.

Based on work I did for the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.