The Collaborative International Dictionary of English v.0.48:

Voluptuous \Vo*lup"tu*ous\, a. [F. voluptueux, L. voluptuosus,
   fr. voluptas pleasure, volup agreeably, delightfully;
   probably akin to Gr. ? to hope, ? hope, and to L. velle to
   wish. See Voluntary.]
   1. Full of delight or pleasure, especially that of the
      senses; ministering to sensuous or sensual gratification;
      exciting sensual desires; luxurious; sensual.
      [1913 Webster]

            Music arose with its voluptuous swell. --Byron.
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            Sink back into your voluptuous repose. --De Quincey.
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   2. Given to the enjoyments of luxury and pleasure; indulging
      to excess in sensual gratifications. "The jolly and
      voluptuous livers." --Atterbury.
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            Softened with pleasure and voluptuous life.
                                                  --Milton.
      [1913 Webster] -- Vo*lup"tu*ous*ly, adv. --
      Vo*lup"tu*ous*ness, n.
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      [1913 Webster]

WordNet (r) 3.0 (2006):

voluptuousness
    n 1: the quality of being attractive and exciting (especially
         sexually exciting); "he thought she was really hot stuff"
         [syn: hot stuff, voluptuousness]
    2: the property of being lush and abundant and a pleasure to the
       senses [syn: luxuriance, lushness, voluptuousness]
    3: the quality of having a well-rounded body [syn:
       curvaceousness, shapeliness, voluptuousness]