The Collaborative International Dictionary of English v.0.48:

Litany \Lit"a*ny\ (l[i^]t"[.a]*n[y^]), n.; pl. Litanies
   (l[i^]t"[.a]*n[i^]z). [OE. letanie, OF. letanie, F. litanie,
   L. litania, Gr. litanei`a, fr. litaney`ein to pray, akin to
   li`tesqai, li`ssesqai, to pray, lith` prayer.]
   A solemn form of supplication in the public worship of
   various churches, in which the clergy and congregation join,
   the former leading and the latter responding in alternate
   sentences. It is usually of a penitential character.
   [1913 Webster]

         Supplications . . . for the appeasing of God's wrath
         were of the Greek church termed litanies, and rogations
         of the Latin.                            --Hooker.
   [1913 Webster]