Small stones (6)
'small stones' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for gravel that I've seen before include "Driveway surface" , "Stone mixture for paths" , "Small loose stones" , "Coarse sand with small stones used for roads, driveways etc" , "Loose fragments of rock" .)
'small stones' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for pebbles that I've seen before include "Small, smooth, rounded rocks" , "Small round stones, as on beach" , "Small rounded stones" .)