The Collaborative International Dictionary of English v.0.48:

Chasseur \Chas`seur"\, n. [F., a huntsman. See Chase to
   pursue.]
   1. (Mil.) One of a body of light troops, cavalry or infantry,
      trained for rapid movements.
      [1913 Webster]

   2. An attendant upon persons of rank or wealth, wearing a
      plume and sword.
      [1913 Webster]

            The great chasseur who had announced her arrival.
                                                  --W. Irving.
      [1913 Webster]