regolith

noun

reg·​o·​lith ˈre-gə-ˌlith 

: unconsolidated residual or transported material that overlies the solid rock on the earth, moon, or a planet

Examples of regolith in a Sentence

Recent Examples on the Web

The scientists surmised that this occurs because lunar dirt, called regolith, that piled up around the crater as a result of the impact is less dense and therefore less able to retain heat. — Adam Kovac, Scientific American, 22 Sep. 2026

But the gelatin-and-yeast concrete could offer some advantages over some of the other leading ideas for making building materials on Mars, most of which rely on heating and melting regolith to form bricks and support beams. — Kiona N. Smith, Space.com, 17 Sep. 2026

This means that helium-3 has been striking the lunar soil, or regolith, for a long time. — Eric Berger, ArsTechnica, 26 Aug. 2026

Orbital imagery has shown that unlike its heavily cratered sibling moon, Phobos, which means fear in ancient Greek, Deimos is much smoother — and covered in a perplexing layer of dust and rubble called regolith. — Ashley Strickland, CNN Money, 20 Aug. 2026

Word History

Etymology

Greek rhēgos blanket + English -lith; akin to Greek rhezein to dye — more at raga

First Known Use

1897, in the meaning defined above