Vichy n 1: 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
Vichy water \Vi"chy wa`ter\, prop. n. A mineral water found at Vichy, France. It is essentially an effervescent aqueous solution of sodium, calcium, and magnesium carbonates, with sodium and potassium chlorides; also, by extension, any artificial or natural water resembling in composition the Vichy water proper. Called also, colloquially, {Vichy}. [1913 Webster]