KYRIE (in full kyrie eleison, or eleeson, Gr. idipit iXitjaov; cf. Ps. cxxii. 3, Matt. xv. 22, etc., meaning " Lord, have mercy "), the words of petition used at the beginning of the Mass and in other offices of the Eastern and Roman Churches. In the Anglican Book of Common Prayer the Kyrie is introduced into the orders for Morning and Evening Prayer, and also, with an additional petition, as a response made by the congregation after the reading of each of the Ten Commandments at the opening of the Communion Service. These responses are usually sung, and the name Kyrie is thus also applied to their musical setting. In the Lutheran Church the Kyrie is still said or sung in the original Greek. " Kyrielle," a shortened form of Kyrie eleison, is applied to eight-syllabled four-line verses, the last line in each verse being repeated as a refrain.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)