Leach definition

leche "leachate" from unattested *læċe, *leċe "muddy stream" from . Akin to leccan "to water, moisten". More at leak.

A quantity of wood ashes, through which water passes, and thus imbibes the alkali.
A tub or vat for leaching ashes, bark, etc.

To purge a soluble matter out of something by the action of a percolating fluid.

Heavy rainfall can leach out minerals important for plant growth from the soil.

The mercury in dental amalgams can leach out from the fillings into the body.