boulder

noun boul·der \ ˈbōl-dər \

variants: or less commonly bowlder

|Updated on: 14 Jun 2018

Definition of boulder

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

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bouldered

play \-dərd\ adjective

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bouldery

play \-d(ə-)rē\ adjective

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Recent Examples of boulder from the Web

These rocks, called diamictites, are made of huge boulders transported great distances by glaciers.

— lucas joel, Science | AAAS, "Ancient Earth froze over in a geologic instant," 7 June 2018
His workout, called misogi, consists of Korver running underwater while carrying a bunch of heavy boulders.

— andrew joseph, For The Win, "A reminder that Kyle Korver has the NBA's craziest workout regimen," 21 May 2018
Geologists have warned that the volcano could become even more violent, with increasing ash production and the potential that future blasts could hurl boulders the size of cows from the summit.

— Bloomberg.com, "'Excited And Scared': Hawaii Volcano Spews Huge Cloud of Ash," 18 May 2018
Geologists have warned that the volcano could become even more violent, with increasing ash production and the potential that future blasts could hurl boulders the size of cows from the summit.

— caleb jones and sophia yan, Fox News, "Light coats of gritty ash fall near erupting Hawaii volcano," 18 May 2018
As a result, Hawaii Volcanoes National Park has been closed to keep people out of reach of projectile boulders.

— scott k. johnson, Ars Technica, "Here’s what’s going on with Hawaii’s erupting volcano," 11 May 2018
Geologists are warning a possible explosion at the summit of Kilauea could be the largest in nearly 100 years, hurling boulders the size of refrigerators.

— CBS News, "Hawaii Kilauea volcano eruption: More Big Island residents told to be prepared to evacuate," 11 May 2018
The steep ledge of Palisade Mountain rises just across the highway, while the sound of water crashing over boulders in Big Thompson River often fills the piney mountain air.

— daniel cusick, Scientific American, "Colorado Charts a New Path Away from Floodwaters," 25 May 2018
Low boulders now sit in place to help shelter Cocles, with its reggae bar and cafes serving rice and beans, where tourists cycle past fruit stalls selling lychees and soursop and signs warn of sloths crossing the beach road.

— sophie hares, The Christian Science Monitor, "Costa Rica's coast struggles to survive against rising seas," 25 May 2018

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.

Origin and Etymology of 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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First Known Use: 1607

in the meaning defined above

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