Refers to a small, often insignificant stone or pebble, typically one that can be picked up or kicked. The word carries a casual, everyday feel.
A small stone was lying on the road.
The child is picking up and collecting pebbles.
Standard common spelling; the kanji 石 is used with the kana ころ.
Rarely used kanji form; the reading いしころ is not standard for this kanji combination.
Compound of 石 (いし, 'stone') and ころ, a suffix meaning 'small round thing' or 'lump'. The exact origin of ころ is uncertain, but it appears in other words like ちびころ (small child) and いぬころ (puppy).