boulder

noun boul·der \ ˈbōl-dər \

variants: or less commonly bowlder

Definition of boulder

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

—

bouldered

play \-dərd\ adjective

—

bouldery

play \-d(ə-)rē\ adjective

See boulder defined for English-language learners

See boulder defined for kids

Recent Examples of boulder from the Web

Challenge yourself to a workout at Whitney Peak’s Base Camp indoor boulders or 164-foot outdoor climbing wall, officially the world’s largest.

— heather platt, Los Angeles Magazine, "Reno: It’s Not Just The Place You Ignore While Skiing in Tahoe Anymore," 28 Aug. 2017
On one side of the road might sit shanties with chickens wandering about and satellite dishes anchored onto mossy boulders.

— sam kean, Science | AAAS, "When will yellow fever strike Brazil again? Monkeys and mosquitoes hold clues," 17 Aug. 2017
Kendall Jenner's (understandable) disdain for over-the-shoulder boulder holders is in the spotlight once again — but this time, she's also ditched pretty much all her other clothes, too.

— andrea park, Allure, "Kendall Jenner Matches Her Thong to Her Lipstick in New La Perla Lingerie Campaign Image," 1 Aug. 2017
Virgin Gorda Island is also known for its infamous Baths, a grouping of otherworldly natural granite boulders that form beautiful rock pools where the water creeps in.

— lori keong, Marie Claire, "Weekend Trip Guide: Where to Stay, Eat, and Drink in the British Virgin Islands," 14 July 2017
The fires burned among boulders and brush in a small strip of land between the freeway and the Tavern Road exit lanes.

— pauline repard, sandiegouniontribune.com, "Small fires ignite along I-8 in Alpine, right lane blocked for fire crews," 13 July 2017
According to a 2012 story by AL.com's Kelly Kazek, farmer Leonard Dawson began the rock zoo in the '70s when someone moved a boulder on his property.

— AL.com, "This Alabama zoo is truly like no other -- because the animals are made of rock," 12 July 2017
This assumption was tested a decade later in pikas, small mountain-dwelling rodents that nest among boulders and also happen to be the inspiration for the Pokemon Pikachu.

— liza gross, Smithsonian, "How Fear of Humans Can Ripple Through Food Webs and Reshape Landscapes," 12 July 2017
Her determination, though, is a rushing stream that washes past boulders.

— fred dickey, sandiegouniontribune.com, "Quadriplegic exemplifies meaning of her name: hope," 3 July 2017

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

NEW! Time Traveler

First Known Use: 1607

See Words from the same year