1. (with reference to a soluble chemical or mineral) drain away from soil, ash, or similar material by the action of percolating liquid, especially rainwater: "the nutrient is quickly leached away"
▪ subject (soil, ash, etc.) to a leaching process:"ash is readily leached"
Word OriginOld Englishleccan ‘to water’, of West Germanic origin. The current sense dates from the mid 19th century.