Pebble (?), n. [AS. papolstān; cf. L. papula pimple, mote. See Stone.] 1. A small roundish piece of stone; especially, a stone worn and rounded by the action of water; a pebblestone. “The pebbles on the hungry beach.” Shak.
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As children gathering pebbles on the shore. Milton.
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2. Transparent and colorless rock crystal; as, Brazilian pebble; -- so called by opticians.
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Pebble powder, slow-burning gunpowder, in large cubical grains. -- Scotch pebble, varieties of quartz, as agate, chalcedony, etc., obtained from cavities in amygdaloid.
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