Source : Webster's Revised Unabridged Dictionary (1913)

Requin \Re"quin\ (r?"kw?n), n. [F., fr. reqiem a Mass sung for
   the dead. See {Requiem}.] (Zo["o]l.)
   The man-eater, or white shark ({Carcharodon carcharias}); --
   so called on account of its causing requiems to be sung.

Source : WordNet®

Carcharodon carcharias
     n : large aggressive shark widespread in warm seas; known to
         attack humans [syn: {great white shark}, {white shark}, {man-eater},
          {man-eating shark}]