IPA: /ˈboʊldərər/
KK: /ˈboʊldərər/
A person who climbs on large rocks or boulders without using ropes or harnesses.
The boulderer skillfully navigated the challenging rock formations.
Boulderer → The word is formed from "boulder" (from Middle English *boulter*, meaning a large rock) and "-er" (meaning a person who). A boulderer is a person who climbs boulders or large rocks.
Think of someone who climbs 'large rocks' ('boulder') — the '-er' just means a person. A boulderer is someone who climbs these big stones.