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

But animals don’t appear to be interested in all forms of action, such as the tumble of a boulder or the wind in a tunnel. — Literary Hub, 14 Aug. 2026

More than once, the script references Sisyphus, one of the few characters in fiction who can rival its protagonist for bad luck with boulders. — Justin Chang, New Yorker, 14 Aug. 2026

Our recent drought is so severe — soon our drinking water may come from the Susquehanna River via a 36-mile series of tunnels and pipes — that large boulders are easily accessible. — Carl R. Gold, Baltimore Sun, 14 Aug. 2026

Chris, who was seated beside her husband in the backseat, told KCTV that the boulder crushed Rex’s skull and pushed bone into his brain stem. — Rachel Raposas, PEOPLE, 14 Aug. 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 population 97,385