a yellow to light-gray, slightly water-soluble powder, CaS, having the odor of rotten eggs when moist: used chiefly in the preparation of luminous paint, hydrogen sulfide, and as a depilatory in cosmetics.
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calcium sulfide,
a yellow or grayish powder produced by heating calcium sulfate and charcoal, used as a depilatory and in luminous paints. Formula: CaS
Useful english dictionary. 2012.