Kyrie eleison

early 13c., a Greek liturgical formula adopted untranslated into the Latin mass, literally "lord have mercy" (Psalms cxxii.3, Matthew xv.22, xvii.15, etc.). From kyrie, vocative of kyrios "lord, master" (see church (n.)) + eleeson, aorist imperative of eleo "I have pity on, show mercy to," from eleos "pity, mercy" (see alms). Hence, the corresponding part of a musical setting of the Mass or Anglican Communion.