Vichy (adj.)

in reference to collaborationist government of France, 1940, from the name of the city in department of Allier in central France, famous for mineral springs, seat 1940-44 of the French government formed under Nazi occupation and headed by Pétain. The place name is of uncertain origin.

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Definitions of Vichy from WordNet

Vichy (n.)
a town in central France (south of Paris) noted for hot mineral springs; was capital of the unoccupied part of France during World War II;