The Collaborative International Dictionary of English v.0.48:

Sucrose \Su"crose`\, n. [F. sucre sugar. See Sugar.] (Chem.)
   A common variety of sugar found in the juices of many plants,
   as the sugar cane, sorghum, sugar maple, beet root, etc. It
   is extracted as a sweet, white crystalline substance which is
   valuable as a food product, and, being antiputrescent, is
   largely used in the preservation of fruit. Called also
   saccharose, cane sugar, etc. At one time the term was
   used by extension, for any one of the class of isomeric
   substances (as lactose, maltose, etc.) of which sucrose
   proper is the type; however this usage is now archaic.
   [1913 Webster +PJC]

   Note: Sucrose proper is a dextrorotatory carbohydrate,
         C12H22O11. It does not reduce Fehling's solution, and
         though not directly fermentable, yet on standing with
         yeast it is changed by the diastase present to invert
         sugar (dextrose and levulose), which then breaks down
         to alcohol and carbon dioxide. It is also decomposed to
         invert sugar by heating with acids, whence it is also
         called a disaccharate. Sucrose possesses at once the
         properties of an alcohol and a ketone, and also forms
         compounds (called sucrates) analogous to salts. Cf.
         Sugar.
         [1913 Webster]

WordNet (r) 3.0 (2006):

sucrose
    n 1: a complex carbohydrate found in many plants and used as a
         sweetening agent [syn: sucrose, saccharose]