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

The road was reopened a few hours after the crash happened when CalTrans crews helped push the boulder out of the way, firefighters said. —Dean Fioresi, CBS News, 26 Dec. 2025

Rocks and boulders added to the stage production, anchored by an arch with hieroglyphic text added for extra detail. —Demicia Inman, VIBE.com, 22 Dec. 2025

There’s also a small but shady Engelmann oak grove set among boulders and a number of short hills to climb for those seeking a workout. —Maura Fox, San Diego Union-Tribune, 19 Dec. 2025

Why was one of the most viral Reels of 2025 a surreal sequence showing a heavyset woman shattering a glass bridge in China with a boulder? —Miles Klee, Rolling Stone, 14 Dec. 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

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 population 97,385