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 landscape in Ponza is changing fast, with iconic shores such as Chiaia di Luna and Cala Forna now ghosted due to falling boulders. —Kristina Kasparian, Travel + Leisure, 15 Mar. 2026

Some steep slopes need a little more engineering in the way of terracing, retaining walls or placement of boulders at different water inflection points on the embankment. —The San Diego Union Tribune, San Diego Union-Tribune, 14 Mar. 2026

Bonsai’s lone boulder and tiny trees are a photography magnet, while Secret Cove’s clear shallows make for the perfect break after a morning of exploring. —Ted Alvarez, Outside, 9 Mar. 2026

The bodies were found packed under 8 feet of snow in a small depression ringed with trees and boulders, the Sierra Avalanche Center reported. —Sacbee.com, 9 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