Source : Webster's Revised Unabridged Dictionary (1913)

Red Cross \Red Cross\
   1. The crusaders or the cause they represented.

   2. A hospital or ambulance service established as a result
      of, though not provided for by, the Geneva convention of
      1864; any of the national societies for alleviating the
      sufferings of the sick and wounded war, also giving aid
      and relief during great calamities; also, a member or
      worker of such a society; -- so called from the badge of
      neutrality; the Geneva cross.

Source : WordNet®

Red Cross
     n : an international organization that cares for the sick or
         wounded or homeless in wartime