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