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 adjective
bouldery 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.
At the scene, first responders found that a car had apparently gone off the road, crashed into several boulders and hit multiple boats before coming to a stop. Cecilio Padilla, CBS News, 12 June 2026 Tipsword eventually struck a boulder and was arrested. Devoun Cetoute, Miami Herald, 10 June 2026 Those rings consist of countless billions of particles, the bulk of which are tiny, measuring from about the size of a grain of sand up to car-sized boulders, though the largest boulders are estimated to range anywhere from 30 to 60 feet (9 to 18 meters) across. Joe Rao, Space.com, 9 June 2026 Move good hiding spots like logs, plant pots, and large boulders further from the pool. Brandee Gruener, Southern Living, 7 June 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

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Cite this Entry

“Boulder.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/boulder. Accessed 20 Jun. 2026.

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 population 97,385

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