The Collaborative International Dictionary
Leach \Leach\, n. [Written also letch.] [Cf. As. le['a]h lye, G. lauge. See Lye.]
A quantity of wood ashes, through which water passes, and thus imbibes the alkali.
A tub or vat for leaching ashes, bark, etc.
Leach tub, a wooden tub in which ashes are leached.