Source : Webster's Revised Unabridged Dictionary (1913)

Melodious \Me*lo"di*ous\, a. [Cf. F. m['e]lodieux. See
   {Melody}.]
   Containing, or producing, melody; musical; agreeable to the
   ear by a sweet succession of sounds; as, a melodious voice.
   ``A melodious voice.'' ``A melodious undertone.''
   --Longfellow. -- {Me*lo"di*ous*ly}, adv. --
   {Me*lo"di*ous*ness}, n.

Source : WordNet®

melodiousness
     n : the property of having a melody [syn: {tunefulness}]