req·ui·em (rĕkwē-əm, rēkwē-)
1. Requiem Roman Catholic Church
a. A mass for a deceased person.
b. A musical composition for such a mass.
2. A hymn, composition, or service for the dead.
[Middle English, from Latin, accusative of requiēs, rest, the first word of the mass for the dead : re-, re- + quiēs, quiet; see kweiə- in the Appendix of Indo-European roots.]
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