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.
The boulder, for one thing, was only some twenty feet high. D. T. Max, New Yorker, 15 Sep. 2025 Tracking the moon’s rolling stones Finding recent boulder falls on the moon has been a long-standing challenge. Rupendra Brahambhatt, Interesting Engineering, 14 Sep. 2025 One of the most striking features lies between the kitchen and the dining room, where water runs over a massive boulder from the Flatirons. Tori Latham, Robb Report, 10 Sep. 2025 After the ice melted some 600,000 years ago, the 28-ton red Siouxan quartzite boulder stood more than 10 feet above the water. Chadd Scott, Forbes.com, 10 Sep. 2025 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 17 Sep. 2025.

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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