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

In Dana Point, coastal homeowners on Beach Road — part of the Capistrano Bay Community Services District — have been racing to install protection like a boulder barrier, according to a statement from the city. — Los Angeles Times, 28 Sep. 2026

Hairpin turns, narrow gaps between boulders and trees, and clouds of dust kept us crawling most of the way up, which was fine with me. — Patricia Doherty, Travel + Leisure, 27 Sep. 2026

The pair climbed along the edge of Earnslaw Burn’s peak, across boulders in the Routeburn River, and through the Routeburn Valley. — Emily Zemler, Condé Nast Traveler, 25 Sep. 2026

That triggered 30-foot-high waves of boulders, water and ice that surged for miles downstream. — Mamita Bhandari, NPR, 23 Sep. 2026

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

Rhymes for boulder

• bolder
• bowlder
• colder
• folder
• golder
• holder
• molder
• moulder
• older
• polder
• shoulder
• beholder

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