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 a dirt road in Imperial County leading toward the Mexico border, the tracks of rare wild sheep press into dusty tire tracks, amid jumbled boulders and spindly ocotillo. —Lila Seidman, Los Angeles Times, 1 Feb. 2026

Go for one overlooking the pool in the main building, or against the boulders on the backside of the complex across from the main entrance. —Lizbeth Scordo, Condé Nast Traveler, 31 Jan. 2026

Massive columns, slender spires and impossibly balanced boulders loom above the timber. —Roger Naylor, AZCentral.com, 29 Jan. 2026

Vandals defaced a boulder and other sites at Yosemite National Park with graffiti over the weekend. —Stephen Sorace , Greg Wehner, FOXNews.com, 28 Jan. 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