Forms: 3–6 bulder-ston(e, 7 boother-, bowther-stone, 8–9 bowlder-stone, 7– boulder-stone. [Etymology obscure. With ME. bulderston, cf. Sw. dial. (E. Gothl.) bullersten a large stone in a stream, one which makes a rumbling noise in the water, as opposed to klappersten a smaller pebble; f. Sw. buller noise, roar, bullr-a to roar, rumble + sten = STONE. This gives a passable sense; but no corresponding word is known elsewhere in Swedish, Old or New, Icelandic, Norwegian, or Danish; so that actual relation between the North. Eng. and Swedish dialect word cannot be asserted.
No words answering to Sw. buller, bullra, exist in Old or New Icelandic, but Da. has bulder ‘tumbling noise,’ buldre ‘to racket, rattle, make a noise.’ If either these words were in use in North. Eng., or a compound *bulder-steen in Da., it would be natural to find here the origin of the Eng. word; but no such connecting links are found. The verb and sb. seem indeed to exist in the Sc. buller ‘to bellow, roar,’ buller ‘bellowing, roar, loud gurgling sound,’ but this is not quite the shade of sense required, while the form it would yield is not bulder-, bowlder-, bowther-, or boother-, as actually found in North. Eng. dial., but *buller-stane, which is not found.]
A rounded water-worn stone larger than a pebble, a cobble-stone (= BOULDER sb. 1). Also, in later use, = BOULDER 2.
a. 1300. Havelok, 1790. He gripen sone a bulder ston, And let it fleye.
1523. Fitzherb., Husb., § 15. Bulder stones … wold weare the yren to soone.
1635. Brereton, Trav. (1844), 101. The best paved street with bowther stones … that I have seen.
1792. Gentl. Mag., April, 350. Large bowlder stones.
1861. Mrs. Norton, Lady La G., I. 224. The ground is rough with boulder stones.
1879. Jenkinson, Guide to Lake Dist., 148. Borrowdale … The Bowder Stone is an immense detached block … computed to weigh 1971 tons.
1884. S. E. Dawson, Hand-bk. Canada, 295. A very singular plateau, covered to a great depth with rounded boulder-stones.
