boul·​der | \ ˈbōl-dər How to pronounce boulder (audio) \
variants: or less commonly

Definition of boulder

 (Entry 1 of 2)

: a detached and rounded or much-worn mass of rock


geographical name
Boul·​der | \ ˈbōl-dər How to pronounce Boulder (audio) \

Definition of Boulder (Entry 2 of 2)

city northwest of Denver in north central Colorado population 97,385

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Other Words from boulder


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: Noun The fourth and final boulder problem Natalia Grossman faced in the IFSC Boulder World Cup women’s final in Salt Lake City last weekend hadn’t discriminated against her competition. The Salt Lake Tribune, 28 May 2021 The Warriors trailed virtually the entire game, pushing the boulder uphill all night. Ann Killion, San Francisco Chronicle, 21 May 2021 The massive extraterrestrial boulder is made of foam covered with reflective glass beads, yet appears to be far more substantial. Washington Post, 30 Apr. 2021 If Mare paused for a second while pushing her boulder up that mountain, standing beside Colin for a bit might be kind of nice. Roxana Hadadi, Vulture, 9 May 2021 One boulder snagged the attention of the OSIRIS-REx researchers. Ashley Strickland, CNN, 20 Apr. 2021 One of the most iconic features is the teetering enormous sandstone boulder atop Balanced Rock, presumed to weigh about 3,677 tons. Nick Kontis, USA Today, 12 Apr. 2021 This past year and a half has been a boulder onto a sheet of ice for marketing. Adrian Dayton, Forbes, 9 Apr. 2021 The boulder-size asteroid's journey to our planet began 22 million years ago, according to new research. Ashley Strickland, CNN, 1 May 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'boulder.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of boulder


1607, in the meaning defined above

History and Etymology for boulder


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

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Time Traveler for boulder

Time Traveler

The first known use of boulder was in 1607

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Statistics for boulder

Last Updated

10 Jun 2021

Cite this Entry

“Boulder.” Dictionary, Merriam-Webster, Accessed 12 Jun. 2021.

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More Definitions for boulder



English Language Learners Definition of boulder

: a very large stone or rounded piece of rock


boul·​der | \ ˈbōl-dər \

Kids Definition of boulder

: a very large rounded piece of rock

More from Merriam-Webster on boulder

Nglish: Translation of boulder for Spanish Speakers

Britannica English: Translation of boulder for Arabic Speakers Encyclopedia article about boulder


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