boulder

noun

boul·​der ˈbōl-dər How to pronounce boulder (audio)
variants or less commonly bowlder
: a detached and rounded or much-worn mass of rock
bouldered
ˈbōl-dərd How to pronounce boulder (audio)
adjective
bouldery
ˈbōl-d(ə-)rē How to pronounce boulder (audio)
adjective

Examples of boulder 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.
This award-winning concrete dome in the high desert is designed to look like a UFO, with soaring curved ceilings, plaster walls the color of the moon, and furniture carved from boulders. — Angela Tafoya, Vogue, 27 Oct. 2026 Since landing on Mars back in 2021, Perseverance has observed, sampled and studied a wide variety of rocks, boulder fields, Martian slopes and more. — Chelsea Gohd, Space.com, 27 Oct. 2026 By sampling a boulder’s upper surface and counting the beryllium, researchers could learn how long it has been uncovered. — Jacek Krywko, ArsTechnica, 24 Oct. 2026 Crews are installing boulders to separate the roadway from the waves. — Los Angeles Times, 24 Oct. 2026 See All Example Sentences for boulder

Word History

Etymology

short for boulder stone, from Middle English bulder ston, partial translation of a word of Scandinavian origin; akin to Swedish dialect bullersten large stone in a stream, from buller noise + sten stone

First Known Use

1607, in the meaning defined above

Time Traveler
The first known use of boulder was in 1607

Rhymes for boulder

See All Rhymes for boulder

Browse Nearby Words

boulangerite
boulder
Boulder
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Cite this Entry

“Boulder.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/boulder. Accessed 1 Nov. 2026.

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Kids Definition

boulder

noun
boul·​der ˈbōl-dər How to pronounce boulder (audio)
: a large detached and rounded or worn mass of rock

Geographical Definition

Boulder

geographical name

Boul·​der ˈbōl-dər How to pronounce Boulder (audio)
city northwest of Denver in north central Colorado

More from Merriam-Webster on boulder

Britannica.com: Encyclopedia article about boulder

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