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.
Team members then used the rounded barrel structures on Bruno to scoop the crushed rock known as regolith, and continue working through the run. — Richard Tribou, The Orlando Sentinel, 20 May 2026 The silver rover then maneuvers over a bed of sand and the excavator rotates to scrape away and collect layers of simulated lunar regolith. — Brandon Lingle, San Antonio Express-News, 17 Mar. 2026 The regolith also lacks the microbiome found in Earth soils, and its powder-like consistency doesn't allow water to easily filter through it, according to the paper. — Julia Jacobo, ABC News, 5 Mar. 2026 However, when the Apollo missions brought back samples from the moon between 1969 and 1972, scientists found that the lunar regolith was bone dry. — Keith Cooper, Space.com, 14 Apr. 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 7 Jul. 2026.

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More from Merriam-Webster on regolith

Britannica.com: Encyclopedia article about regolith

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