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 bouldered (audio) \ adjective
bouldery \ ˈbōl-​d(ə-​)rē How to pronounce bouldery (audio) \ adjective

Examples of boulder in a Sentence

Recent Examples on the Web: Noun The uphill portion on the Mormon Trail crawls 700 feet up Neighborhood Canyon, dodging massive boulders, slickrock corridors and desert flora adapted to South Mountain’s craggy environs. Mare Czinar, azcentral, "This is one of Phoenix's best loved hikes. Here's why," 8 Jan. 2020 The long wall was made up of big boulders, some of which could be more than 3 feet (1 meter) wide and weigh more than a metric ton (1,000 kg). Megan Gannon, Smithsonian, "Oldest Known Seawall Discovered Along Submerged Mediterranean Villages," 18 Dec. 2019 One boulder, affectionately referred to as Mt. Doom, stands about 32 feet above the spot where Bennu is slated to touch down. Jennifer Leman, Popular Mechanics, "X Marks the Spot: OSIRIS-Rex Is Headed to Nightingale Crater," 13 Dec. 2019 The creek was channelized in the 1930s, using boulders, and the woody debris that fell naturally into the creek, creating the pools, was removed. Peter Fimrite,, "Major push to save Muir Woods salmon run includes creek, habitat work," 10 Dec. 2019 Every sound seems amplified, every pebble under your sleeping bag feels like a boulder, and your hunting buddy’s snoring can give you homicidal thoughts. The Editors, Field & Stream, "Three Tricks for Sleeping Better in Camp," 7 Dec. 2019 The work was arduous—removing granite boulders, planting vines by hand—but the Fellowship prized the clarity and camaraderie that came from collective physical labor. Rachel Monroe, The New Yorker, "How Natural Wine Became a Symbol of Virtuous Consumption," 18 Nov. 2019 Take, for instance, the color white, how to choose a yard boulder, and how to throw away a computer. Marni Jameson,, "An homage to the humble basket, the household workhorse," 7 Nov. 2019 It’s packed with 60 pieces, including 24 dinos plus accessories like trees, boulders, and a volcano. Nicole Saporita, Good Housekeeping, "The 2019 Good Housekeeping Best Toy Awards," 18 Oct. 2019

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

25 Jan 2020

Cite this Entry

“Boulder.” Dictionary, Merriam-Webster, Accessed 16 Feb. 2020.

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More Definitions for boulder


How to pronounce Boulder (audio)

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

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More from Merriam-Webster on boulder

Rhyming Dictionary: Words that rhyme with boulder

Spanish Central: Translation of boulder

Nglish: Translation of boulder for Spanish Speakers

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

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