regolith

American

[reg-uh-lith] / ˈrɛg ə lɪθ /

noun

mantle rock.

regolith British

/ ˈrɛɡəlɪθ /

noun

the layer of loose material covering the bedrock of the earth and moon, etc, comprising soil, sand, rock fragments, volcanic ash, glacial drift, etc

"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

regolith Scientific

/ rĕg′ə-lĭth′ /

The layer of rock and mineral fragments that rests on bedrock and is produced by the weathering of rocks. Regolith constitutes the surface of most land.

Etymology

Origin of regolith

1895–1900; < Greek rhêgo ( s ) rug, blanket + -lith

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

"We're not ignoring the fact that we've got to process large amounts of regolith," says Meyerson.

From BBC • Jun. 16, 2026

He has long advocated recovering helium-3 from lunar regolith.

From BBC • Jun. 16, 2026

It will decide where to mine regolith and extract the ice water that, separated into hydrogen and oxygen, becomes rocket fuel for everything that comes next.

From The Wall Street Journal • Apr. 29, 2026

Interlune plans to estimate how much helium-3 is in the lunar regolith — that is, moon debris — through a lunar rover mission carried out with Astrolab in 2028.

From MarketWatch • Mar. 31, 2026

In return, Sporosarcina secretes natural polymers that support mineral formation and help bind regolith.

From Science Daily • Jan. 6, 2026

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023