pebble
n. countablen. a small, smooth stone that has been shaped by water or wind. You often find them on beaches or at the bottom of rivers.
n. a small, smooth, rounded stone, typically between 4 and 64 millimetres in diameter. Often shaped by the abrasive action of water in fluvial or coastal environments.
The child threw a small pebble into the lake.
The beach was covered in smooth grey pebbles that rattled every time a wave pulled back into the sea.
Geologists can determine the history of a riverbed by examining the composition and roundness of the pebbles found within the sediment layers.
From Middle English pibel (also in pibleston), from Old English papolstān (“pebble-stone”), from Old English papol, pyppel, *pæbbel of unknown origin + Old English stān. Compare Albanian popël.
Commonly used in the plural when describing terrain or surfaces.