boulder
boul.der \'bo-l-d*r\ \-d*rd\ \-d(*-)re-\ n [short for boulder stone, fr. ME bulder ston, part trans. of a word] of Scand origin; akin to Sw dial. bullersten large stone in a stream, fr. buller noise + sten stone : a detached and rounded or much-worn mass of rock - boul.dered aj