pebble
n.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.”
Commonly used in the plural when describing terrain or surfaces.
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.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.