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 mega-tsunami wreaked havoc across the landscape, stripping forests down to bare rock, ripping trees out by their roots and hurling boulders. —Ella Nilsen, CNN Money, 6 May 2026

But by the boulder the real action was social and discursive. —Anna Wiener, New Yorker, 4 May 2026

There are several places to get off the boardwalk and walk on the great stone boulders, and at the end of the trail interpretive signs give more information about the area. —Tara Massouleh McCay, Southern Living, 2 May 2026

The most accessible trail in the west park is Signal Hill, which passes boulders covered in Hohokam petroglyphs. —Catherine Garcia, TheWeek, 27 Apr. 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