Source : Webster's Revised Unabridged Dictionary (1913)

Euphonious \Eu*pho"ni*ous\, a.
   Pleasing or sweet in sound; euphonic; smooth-sounding.
   --Hallam. -- {Eu*pho"ni*ous*ly}, adv.

Source : WordNet®

euphonious
     adj 1: having a pleasant sound; "a euphonious trill of silver
            laughter" [syn: {euphonous}] [ant: {cacophonous}]
     2: (of speech or dialect) pleasing in sound; not harsh or
        strident; "her euphonious Southern speech"