The Collaborative International Dictionary of English v.0.48:

Kyrie eleison \Kyr"i*e e*lei"son\n. & interj. [Gr. ky`rie
   'elei^son .]
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   1. (R. C. Ch.) Greek words, meaning "Lord, have mercy upon
      us," used in the Mass, the breviary offices, the litany of
      the saints, etc. --Addis & Arnold.
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   2. The name given to the response to the Commandments, in the
      service of the Church of England and of the Protestant
      Episcopal Church.
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