From Middle English leche (“leachate”), from Old English *lǣċ, *lǣċe (“muddy stream”), from Proto-Germanic *lēkijō (“a leak, drain, flow”), from Proto-Germanic *lēk-, *lak-, *likaną (“to leak, drain”), from Proto-Indo-European *leg(')- (“to leak”). Cognate with Old English leċċan (“to water, moisten”), Old English lacu (“stream, pool, pond”). More at leak, lake.
leach (plural leaches)
- A quantity of wood ashes, through which water passes, and thus imbibes the alkali.
- A tub or vat for leaching ashes, bark, etc.
- (nautical) Alternative spelling of leech.
- (transitive) 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.
- (intransitive) To part with soluble constituents by percolation.
Do not confuse this verb with the verb leech.