regolith

American  

[reg-uh-lith] / ˈrɛg ə lɪθ /

noun

1. mantle rock.

---

regolith British  

/ ˈrɛɡəlɪθ /

noun

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

---

regolith Scientific  

/ rĕg′ə-lĭth′ /

1. 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

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

Although regolith includes minerals and nutrients that plants can use, it also contains heavy metals that may harm plant development.

From Science Daily • Mar. 12, 2026

Analyses of these samples show that the moon's surface layer, known as regolith, contains volatile substances such as water, carbon dioxide, helium, argon, and nitrogen.

From Science Daily • Jan. 5, 2026

In their case, when oxygen-containing bubbles form in the regolith, they do so freely, rather than on the surface of an electrode.

From BBC • Jan. 23, 2025