I. noun
also bowl·der ˈbōldə(r)
( -s )
Etymology: short for boulder stone, from Middle English bulder ston, part translation of a word of Scandinavian origin; akin to Swedish dialect bullersten large stone in a stream, from buller noise (from Old Swedish bulder ) + sten stone; akin to Middle Low German balderen to make a noise, Danish buldre, Lithuanian bildėti, Old English bellan to bellow — more at bellow
: a detached and rounded or much-worn mass of rock from 8 or 10 inches to 10 or more feet in diameter typically carried some distance from the parent rock by natural forces and worn by a stream, ocean waves, or glacier or by weathering in situ — see cobble III 1
II. transitive verb
also bowlder “
( bouldered ; bouldered ; bouldering ˈbōld(ə)riŋ ; boulders )
1. : to make into boulders — used chiefly in past participial form
2. : to smooth (a revolving polishing wheel) by crushing against a quartz stone or boulder