Source : Webster's Revised Unabridged Dictionary (1913)

Orgy \Or"gy\, n.; pl. {Orgies}.
   A frantic revel; drunken revelry. See {Orgies}

Orgies \Or"gies\, n. pl.; sing. {Orgy}.

   Note: [The singular is rarely used.] [F. orgie, orgies, L.
         orgia, pl., Gr. ?; akin to ? work. See {Organ}, and
         {Work}.]
   1. A sacrifice accompanied by certain ceremonies in honor of
      some pagan deity; especially, the ceremonies observed by
      the Greeks and Romans in the worship of Dionysus, or
      Bacchus, which were characterized by wild and dissolute
      revelry.

            As when, with crowned cups, unto the Elian god,
            Those priests high orgies held.       --Drayton.

   2. Drunken revelry; a carouse. --B. Jonson. Tennyson.

Source : WordNet®

orgy
     n 1: any act of immoderate indulgence; "an orgy of shopping"; "an
          emotional binge"; "a splurge of spending" [syn: {binge},
           {splurge}]
     2: secret rite in the cults of ancient Greek or Roman deities
        involving singing and dancing and drinking and sexual
        activity
     3: a wild gathering involving excessive drinking and
        promiscuity [syn: {debauch}, {debauchery}, {saturnalia}, {riot},
         {bacchanal}, {bacchanalia}, {drunken revelry}]