regolith

noun

reg·​o·​lith ˈre-gə-ˌlith How to pronounce regolith (audio)
: 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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The idea is that these proteins could be used as a kind of cement to bind soil or regolith, effectively making a kind of biological cement. — Christopher McFadden, Interesting Engineering, 4 Oct. 2026 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 See All Example Sentences for regolith

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

Time Traveler
The first known use of regolith was in 1897

Browse Nearby Words

regnum
regolith
regorge
See all Nearby Words

Cite this Entry

“Regolith.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/regolith. Accessed 14 Oct. 2026.

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More from Merriam-Webster on regolith

Britannica.com: Encyclopedia article about regolith

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