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

Eventually, rescuers used machinery to remove several heavy boulders from the outcrop, allowing rescuers to yank her to freedom. —Frederick Dreier, Outside Online, 26 Oct. 2024

Its song echoes through this patch of the Daintree Rainforest, part of the Wet Tropics World Heritage Area, bouncing off the same boulders and branches that have existed here since the area was but a small part of the ancient Gondwanan forest that once covered the Australian continent. —Riley Wilson, Condé Nast Traveler, 15 Oct. 2024

The asteroid's rapid rotation period of less than one hour aligns with what scientists would expect from either a large boulder ejected from the Moon's surface or a fragment broken off from a larger lunar object. —Tom Rogers, Newsweek, 25 Nov. 2024

But using higher-frequency blue light is like switching to boulders. —Charlie Wood, Quanta Magazine, 30 Oct. 2024

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

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