a musical setting for a Mass celebrating the dead
"The choir performed a solemn requiem to honor the soldiers who lost their lives in the war."
a Mass celebrated for the dead
"The choir sang a solemn requiem on Sunday to honor those who passed away during the winter flu season."
A mass (especially Catholic) to honor and remember a dead person.
"The experienced angler knew better than to swim near the reef where a requiem was likely lurking in the deep channels."
A large or dangerous shark, specifically, (zoology) a member of the family Carcharhinidae.
The word comes from Middle English and originally Latin, where it meant "rest" or "repose." It was adopted as the title for a mass for the dead because it is the first word of that liturgical service.