boulder

noun

boul·​der ˈbōl-dər 

variants or less commonly bowlder

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

bouldered

ˈbōl-dərd 

adjective

bouldery

ˈbōl-d(ə-)rē 

adjective

Examples of boulder in a Sentence

Recent Examples on the Web

Coopers Rock State Forest, near Morgantown, has 50 miles of trails through boulder fields that offer the occasional view of the Cheat River Gorge below. —Graham Averill, Outside Online, 14 July 2024

Both directions of State Route 87 will be closed for 37 miles overnight on July 14 near Sunflower as crews clean up boulders and debris from a rockslide, the Arizona Department of Transportation announced. —Vivian Barrett, The Arizona Republic, 10 July 2024

But Arcadia Management Area, during the trek’s southernmost third, is home to a set of hulking boulders deposited by the Laurentide Ice Sheet many millennia ago. —Grayson Haver Currin, Outside Online, 7 July 2024

Thirty-foot-wide (10-meter-wide) boulders, as well as concave spots and ridges, litter its surface. —Ashley Strickland, CNN, 6 July 2024

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

Kids Definition

boulder

noun

boul·​der ˈbōl-dər 

: a large detached and rounded or worn mass of rock

Geographical Definition

Boulder

geographical name

Boul·​der ˈbōl-dər 

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