Source : Webster's Revised Unabridged Dictionary (1913)

Joyful \Joy"ful\, a.
   Full of joy; having or causing joy; very glad; as, a joyful
   heart. ``Joyful tidings.'' --Shak.

         My soul shall be joyful in my God.       --Is. lxi. 10.

         Sad for their loss, but joyful of our life. --Pope.
   -- {Joy"ful*ly}, adv. -- {Joy"ful*ness}, n.

Source : WordNet®

joyfulness
     n : the emotion of great happiness [syn: {joy}, {joyousness}]
         [ant: {sorrow}]