[kob-uh
l-stohn] 
| a naturally rounded stone, larger than a pebble and smaller than a boulder, formerly used in paving. |
| cob·ble·stone (kŏb'əl-stōn') n. A naturally rounded paving stone. [Middle English cobelston : obsolete cobel, probably diminutive of cob, round object; see cob + Middle English ston, stone, stone; see stone.] |