The Collaborative International Dictionary of English v.0.48:

Levulose \Lev"u*lose`\ (l[e^]v"[-u]*l[=o]s`), n. [See Levo-.]
   (Chem.)
   A sirupy variety of sugar, rarely obtained crystallized,
   occurring widely in honey, ripe fruits, etc., and hence
   called also fruit sugar; also called fructose. Chemical
   formula: C6H12O6. It is called levulose, because it rotates
   the plane of polarization of light to the left, in contrast
   to dextrose, the other product of the hydrolysis of
   sucrose. [Written also laevulose.]
   [1913 Webster +PJC]

   Note: It is obtained, together with an equal quantity of
         dextrose, by the inversion of ordinary cane or beet
         sugar, and hence, as being an ingredient of invert
         sugar, is often so called. It is fermentable, nearly as
         sweet as cane sugar, and is metameric with dextrose.
         Cf. Dextrose.
         [1913 Webster]

WordNet (r) 3.0 (2006):

levulose
    n 1: a simple sugar found in honey and in many ripe fruits [syn:
         fructose, fruit sugar, levulose, laevulose]