[1] : The Collaborative International Dictionary of English v.0.48

christmas \christ"mas\, n. christ + mass.
   an annual church festival december 25 and in some states a
   legal holiday, in memory of the birth of christ, often
   celebrated by a particular church service, and also by
   special gifts, greetings, and hospitality.
   1913 webster

   christmas box.
   a a box in which presents are deposited at christmas.
   b a present or small gratuity given to young people and
       servants at christmas; a christmas gift.

   christmas carol, a carol sung at, or suitable for,
      christmas.

   christmas day. same as christmas.

   christmas eve, the evening before christmas.

   christmas fern bot., an evergreen north american fern
      aspidium acrostichoides, which is much used for
      decoration in winter.

   christmas flower, christmas rose, the black hellebore, a
      poisonous plant of the buttercup family, which in southern
      europe often produces beautiful roselike flowers
      midwinter.

   christmas tree, a small evergreen tree, set up indoors, to
      be decorated with bonbons, presents, etc., and illuminated
      on christmas eve.
      1913 webster
see also:
christmas box christmas carol christmas day christmas christmas eve christmas fern 
aspidium acrostichoides christmas flower christmas rose christmas tree 

[2] : WordNet (r) 2.0

christmas carol
     n : joyful religious song celebrating the birth of christ syn:
         carol
see also:
carol 

[3] : Moby Thesaurus II by Grady Ward, 1.0

54 moby thesaurus words for "christmas carol":
   brautlied, kunstlied, liebeslied, volkslied, alba, anthem,
   art song, aubade, ballad, ballade, ballata, barcarole, blues,
   blues song, boat song, bridal hymn, brindisi, calypso, canso,
   canticle, canzone, canzonet, canzonetta, carol, cavatina, chanson,
   chant, chantey, croon, croon song, dirge, ditty, drinking song,
   epithalamium, folk song, hymeneal, lay, lied, lilt, love song,
   love-lilt, matin, minstrel song, minstrelsy, national anthem,
   prothalamium, serena, serenade, serenata, song, theme song,
   torch song, war song, wedding song

Christmas Carol >> C Words
Christmas Carol, definition of term: Christmas Carol
christmas+carol_pag1.html

Christmas >> C Words
Christmas, definition of term: Christmas
christmas_pag1.html

Carol >> C Words
Carol, definition of term: Carol
carol_pag1.html

Christmas Flowe >> C Words
Christmas Flowe, definition of term: Christmas Flowe
christmas+flowe_pag1.html

Christmas Tree >> C Words
Christmas Tree, definition of term: Christmas Tree
christmas+tree_pag1.html

Christmas Eve >> C Words
Christmas Eve, definition of term: Christmas Eve
christmas+eve_pag1.html

Christmas Day >> C Words
Christmas Day, definition of term: Christmas Day
christmas+day_pag1.html

Christmas Cactu >> C Words
Christmas Cactu, definition of term: Christmas Cactu
christmas+cactu_pag1.html

Christmas Card >> C Words
Christmas Card, definition of term: Christmas Card
christmas+card_pag1.html