Source : Webster's Revised Unabridged Dictionary (1913)

Ceremony \Cer"e*mo*ny\, n.; pl. {Ceremonies}. [F.
   c['e]r['e]monie, L. caerimonia; perh. akin to E. create and
   from a root signifying to do or make.]
   1. Ar act or series of acts, often of a symbolical character,
      prescribed by law, custom, or authority, in the conduct of
      important matters, as in the performance of religious
      duties, the transaction of affairs of state, and the
      celebration of notable events; as, the ceremony of
      crowning a sovereign; the ceremonies observed in
      consecrating a church; marriage and baptismal ceremonies.

            According to all the rites of it, and according to
            all the ceremonies thereof shall ye keep it [the
            Passover].                            --Numb. ix. 3

            Bring her up the high altar, that she may The sacred
            ceremonies there partake.             --Spenser.

            [The heralds] with awful ceremony And trumpet's
            sound, throughout the host proclaim A solemn
            council.                              --Milton.

   2. Behavior regulated by strict etiquette; a formal method of
      performing acts of civility; forms of civility prescribed
      by custom or authority.

            Ceremony was but devised at first To set a gloss on
            . . . hollow welcomes . . . But where there is true
            friendship there needs none.          --Shak.

            Al ceremonies are in themselves very silly things;
            but yet a man of the world should know them.
                                                  --Chesterfield.

   3. A ceremonial symbols; an emblem, as a crown, scepter,
      garland, etc. [Obs.]

            Disrobe the images, If you find them decked with
            ceremonies. . . . Let no images Be hung with
            C[ae]sar's trophies.                  --Shak.

   4. A sign or prodigy; a portent. [Obs.]

            C[ae]sar, I never stood on ceremonies, Yet, now they
            fright me.                            --Shak.

   {Master of ceremonies}, an officer who determines the forms
      to be observed, or superintends their observance, on a
      public occasion.

   {Not to stand on ceremony}, not to be ceremonious; to be
      familiar, outspoken, or bold.

Source : WordNet®

ceremony
     n 1: a formal event performed on a special occasion; "a ceremony
          commemorating Pearl Harbor" [syn: {ceremonial}, {ceremonial
          occasion}, {observance}]
     2: any activity that is performed in an especially solemn
        elaborate or formal way; "the ceremony of smelling the
        cork and tasting the wine"; "he makes a ceremony of
        addressing his golf ball"; "he disposed of it without
        ceremony"
     3: the proper or conventional behavior on some solemn occasion;
        "an inaugural ceremony"