cob·ble 1 
(kŏbəl)
(kŏbəl)n.
1. A cobblestone.
2. Geology A rock fragment between 64 and 256 millimeters in diameter, especially one that has been naturally rounded.
3. cobbles See cob coal.
tr.v. cob·bled, cob·bling, cob·bles
To pave with cobblestones.
[Short for COBBLESTONE.]