The Collaborative International Dictionary of English v.0.48:

Zouave \Zouave\ (?; 277), n. [F., fr. Ar. Zouaoua a tribe of
   Kabyles living among the Jurjura mountains in Algeria.]
   (Mil.)
   (a) One of an active and hardy body of soldiers in the French
       service, originally Arabs, but now composed of Frenchmen
       who wear the Arab dress.
   (b) Hence, one of a body of soldiers who adopt the dress and
       drill of the Zouaves, as was done by a number of
       volunteer regiments in the army of the United States in
       the Civil War, 1861-65.
       [1913 Webster]