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

This photo series focuses on the clusters of granite boulders that seem to act as coastal guardians along the Nova Scotia waterfront. —Jeanine Barone, Forbes, 9 Jan. 2025

These fortresses tended to take advantage of features like gorges and hilltops for natural defenses, supplementing those with walls of unworked boulders stacked without mortar. —Ars Technica, 9 Jan. 2025

In the back, a bridge leads to a gazebo perched on a boulder that juts over the churning river running behind the property. —Roxana Popescu, New York Times, 3 Jan. 2025

The Holocaust Memorial Garden consists of two granite boulders, on a bed of gravel, surrounded by a stand of birch trees. —Sam Knight, The New Yorker, 2 Jan. 2025

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