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.

See Examples For:

regolith

The Chang'e 6 regolith had an average 20Ne/22Ne ratio of 11.34 ± 0.22.

From Science Daily ● Jul. 21, 2026

Over time, the lunar regolith has stored evidence of this exposure.

From Science Daily ● Jul. 21, 2026

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

From BBC ● Jun. 16, 2026

However, samples of moon dust, or regolith, from the Apollo missions suggest it may be present there at relatively high concentrations.

From BBC ● Jun. 16, 2026

“We don’t know what composition it’s in. Is it large chunks of ice? Is it infused throughout the lunar regolith as small crystals?”

From The Wall Street Journal ● May 15, 2026

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