What did they call the Frenchmen who cooperated with the Germans during

Collaborationism, as a pejorative term, can describe the treason of cooperating with enemy forces occupying one's country. As such it implies criminal deeds in the service of the occupying power, including complicity with the occupying power in murder, persecutions, pillage, and economic exploitation as well as participation in a puppet government.

The use of "collaboration" to mean "traitorous cooperation with the enemy," dates from 1940, originally in reference to the Vichy Regime in France, and other French people who helped Nazi Germany. Since then, the words collaboration and collaborateur possibly have this very pejorative meaning in French (the shortened form collabo only has this pejorative meaning).

The French Resistance is the name used for resistance movements that fought the German occupation of France in World War II and the pro-Nazi German Vichy regime during World War II after the government and the high command of France surrendered in 1940. Resistance groups included groups of armed men (usually referred to as the maquis), publishers of underground newspapers or even cinematography, and escape networks that helped allied soldiers. French Resistance cooperated with Allied secret services (see Office of Strategic Services and Special Operations Executive), especially in providing intelligence on the Atlantic Wall and coordinating sabotage and other actions to contribute to the success of Operation Overlord.