Word Origin & History
boulder1670s, variant of M.E. bulder (c.1300), from a Scandinavian source akin to Swed. dial. bullersten "noisy stone" (large stone in a stream, causing water to roar around it), from bullra "to roar" + sten "stone." Or the first element may be from *buller- "round object," from P.Gmc. *bul-, from PIE *bhel-
(2) "to inflate, swell" (see
bole).