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

On our hike, Jessie Krebs scolds her boots for sliding on a slick, house-size boulder. —Andrew McKean, Outdoor Life, 19 Mar. 2026

Wagner also mentioned the liability from the Airport fire, with the county paying $89 million so far to resolve at least 400 claims from the blaze that was started by a work crew moving boulders. —Tony Saavedra, Oc Register, 17 Mar. 2026

Lee’s stone is actually the footstone to Jackson Pollock’s boulder-sized marker. —Literary Hub, 17 Mar. 2026

Some trails start out as mellow, flat hikes, but eventually turn into steep, rocky scrambles, requiring hikers to use their hands to navigate around boulders or up narrow canyons. —Owen Clarke, Outside, 16 Mar. 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