pebbles is a form of:

Pebble



ENGLISH MEANING
noun
1.
A small roundish stone or bowlder; especially, a stone worn and rounded by the action of water; a pebblestone.
2.
Transparent and colorless rock crystal; as, Brazilian pebble; -- so called by opticians.
verb
1.
(TRANSITIVE) To grain (leather) so as to produce a surface covered with small rounded prominences.