Source : Webster's Revised Unabridged Dictionary (1913)

Liturgy \Lit"ur*gy\, n.; pl. {Liturgies}. [F. liturgie, LL.
   liturgia, Gr. ? a public service, the public service of God,
   public worship; (assumed) ?, ?, belonging to the people,
   public (fr. ?, ?, the people) + the root of ? work. See
   {Lay}, a., and {Work}.]
   An established formula for public worship, or the entire
   ritual for public worship in a church which uses prescribed
   forms; a formulary for public prayer or devotion. In the
   Roman Catholic Church it includes all forms and services in
   any language, in any part of the world, for the celebration
   of Mass.

Source : WordNet®

Liturgy
     n 1: a Christian sacrament commemorating the Last Supper by
          consecrating bread and wine [syn: {Holy Eucharist}, {Eucharist},
           {sacrament of the Eucharist}, {Holy Sacrament}, {Eucharistic
          liturgy}, {Lord's Supper}]
     2: a rite or body of rites prescribed for public worship