Other forms: leaching, leached
To leach is to drain a substance away by water passing through. Nutrients leach away, leaching into groundwater, leached soil.
It is what rain does to soil, carrying soluble nutrients down out of reach of roots — which is why heavy rain on light soil impoverishes it. In pollution it is the mechanism by which landfill and pesticides reach groundwater. In mining, leaching dissolves metal out of crushed ore. Note the homophone leech, the worm, which is a different word.
1verbleachTo drain a substance away by water passing through.
“Chemicals from the old dump leached into the river.”
leach is a draining away.
Old English laec meant a muddy stream, from a Germanic root meaning to leak. Leak and leach come from the same flowing.
Proto-Indo-European
*leǵ- — to leak
Proto-Germanic
*lēkijō — a leak, drain, flow
Old English
*lǣċ
Middle English
leche — leachate; sluggish stream
English, today
leach
Built from
From Middle English leche (“leachate; sluggish stream”), from Old English lǣċ, lǣċe (“muddy stream”), from Proto-Germanic lēkijō (“a leak, drain, flow”) (compare Proto-Germanic lekaną (“to leak, drain”)), from Proto-Indo-European leǵ- (“to leak”). Cognate with Old English leċċan (“to water, moisten”), Old English lacu (“stream, pool, pond”). More at leak, lake.
Etymology from Wiktionary, CC BY-SA
Practised in A Song of Ice and Fire