The DICT Development Group

  acetone \ac"e*tone\ ([a^]s"[-e]*t[=o]n), n. [See Acetic.]
     (Chem.)
     A volatile liquid ({CH3.CO.CH3); pyroacetic spirit; methyl
     ketone; -- obtained by fermentation, the distillation of
     certain acetates, or by the destructive distillation of
     citric acid, starch, sugar, or gum, with quicklime. It is
     commonly used as a solvent.
     [1913 Webster +PJC]
  
     Note: The term was once also applied to a number of bodies of
           similar constitution, more frequently called ketones.
           See Ketone.
           [1913 Webster +PJC]

  acetone
      n 1: the simplest ketone; a highly inflammable liquid widely
           used as an organic solvent and as material for making
           plastics [syn: acetone, propanone, dimethyl ketone]