Source : Webster's Revised Unabridged Dictionary (1913)

Litany \Lit"a*ny\, n.; pl. {Litanies}. [OE. letanie, OF.
   letanie, F. litanie, L. litania, Gr. ?, fr. ? to pray, akin
   to ?, ?, to pray, ? 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.

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

Source : WordNet®

litany
     n 1: any long and tedious address or recital; "the patient
          recited a litany of complaints"; "a litany of failures"
     2: a prayer consisting of a series of invocations by the priest
        with responses from the congregation