The Collaborative International Dictionary of English v.0.48:

Liturgy \Lit"ur*gy\ (l[i^]t"[u^]r*j[y^]), n.; pl. Liturgies
   (l[i^]t"[u^]r*j[i^]z). [F. liturgie, LL. liturgia, Gr.
   leitoyrgi`a a public service, the public service of God,
   public worship; (assumed) le`i:tos, lei^tos, belonging to the
   people, public (fr. lao`s, lew`s, the people) + the root of
   'e`rgon 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.
   [1913 Webster]