Emily Dickinson Lexicon

LEACH, v.t. [Sw. laka, to fall in drops, to distill; läka, to leak; Dan. lekker, to drop, to leak. See Leak. Perhaps L. lix may be from the same root.]

To wash, as ashes, by percolation, or causing water to pass through them, and thus to separate from them the alkali. The water thus charged with alkali, is called lye.