Stage name of a Dutch exotic dancer executed as a German spy in World War I (4,4)
I believe the answer is:
mata hari
(Other definitions for mata hari that I've seen before include "Dutch femme fatale executed by the French in 1917 as a German spy" , "Exotic Dutch dancer, executed by the French as a German, 1917" , "World War I spy" , "Infamous dancer executed as a German spy" , "Famous female spy" .)