The Collaborative International Dictionary of English v.0.48:

Carol \Car"ol\, v. t. [imp. & p. p. Caroled, or Carolled; p.
   pr. & vb. n. Caroling, or Carolling.]
   [1913 Webster]
   1. To praise or celebrate in song.
      [1913 Webster]

            The Shepherds at their festivals
            Carol her goodness.                   --Milton.
      [1913 Webster]

   2. To sing, especially with joyful notes.
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            Hovering swans . . . carol sounds harmonious.
                                                  --Prior.
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The Collaborative International Dictionary of English v.0.48:

Caroling \Car"ol*ing\, n.
   A song of joy or devotion; a singing, as of carols.
   --Coleridge.
   [1913 Webster]

         Such heavenly notes and carolings.       --Spenser.
   [1913 Webster]

WordNet (r) 3.0 (2006):

caroling
    n 1: singing joyful religious songs (especially at Christmas)