verb (used with object)

to dissolve out soluble constituents from (ashes, soil, etc.) by percolation.
to cause (water or other liquid) to percolate through something.

verb (used without object)

(of ashes, soil, etc.) to undergo the action of percolating water.
to percolate, as water.


Origin of leach

1425–75; late Middle English leche leachate, infusion, probably Old English *læc(e), *lec(e), akin to leccan to wet, moisten, causative of leak
Related formsleach·a·ble, adjectiveleach·a·bil·i·ty, nounleach·er, nounun·leached, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for leaching

seep, filter, strain, percolate, extract, filtrate, lixiviate

Examples from the Web for leaching

Contemporary Examples of leaching

  • I submit that a regular program of interaction would go miles in leaching partisan poison from the well in Washington.

    The Daily Beast logo
    Grill Him Again!

    Mark McKinnon

    February 3, 2010

Historical Examples of leaching

British Dictionary definitions for leaching



Bernard (Howell). 1887–1979, British potter, born in Hong Kong




to remove or be removed from a substance by a percolating liquid
to lose or cause to lose soluble substances by the action of a percolating liquid


the act or process of leaching
a substance that is leached or the constituents removed by leaching
a porous vessel for leaching
Derived Formsleacher, noun

Word Origin for leach

C17: variant of obsolete letch to wet, perhaps from Old English leccan to water; related to leak




a variant spelling of leech 2
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for leaching



Old English leccan "to moisten, water, wet, irrigate," (see leak). The word disappears, then re-emerges late 18c. in a technological sense in reference to percolating liquids. Related: Leached; leaching.

Online Etymology Dictionary, © 2010 Douglas Harper

leaching in Medicine




Related formsleach v.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

leaching in Science



The removal of soluble material from a substance, such as soil or rock, through the percolation of water. Organic matter is typically removed from a soil horizon and soluble metals or salts from a rock by leaching. Leaching differs from eluviation in that it affects soluble, not suspended, material and often results in the complete removal of the material from the soil or rock.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.