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.
And the other half of our team is working on getting rid of the perchlorate in Martian regolith. — Lee Billings, Scientific American, 15 Oct. 2026 That’s special and different from other places, like the moon, which doesn’t have nutrients in the regolith. — Charles Q. Choi, Space.com, 9 Oct. 2026 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 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 20 Oct. 2026.

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More from Merriam-Webster on regolith

Britannica.com: Encyclopedia article about regolith

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