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 plaque, installed in May 2024, is embedded in a boulder next to a bench near a grove of trees overlooking Point La Jolla. —Ashley MacKin Solomon, San Diego Union-Tribune, 31 July 2025

Beach Park Fire Chief Tom Stahl and Winthrop Harbor Fire Chief Rocco Campanella sit, looking out at Lake Michigan, where a half-dozen boats trawl along the beachfront around the boulders of the breakwaters. —Joseph States, Chicago Tribune, 30 July 2025

Near the monument that marks the site of the barn where Jews were killed, seven boulders with metal signs in Polish and English detailed a series of false claims, according to the Polish newspaper Gazeta Wyborcza. —Shira Li Bartov, Sun Sentinel, 22 July 2025

These boulders get mixed in with much finer sand and clay to form what’s called a till. —Laura Poppick july 22, Literary Hub, 22 July 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