Refers to a small stone, typically one that can be picked up or thrown. Common in everyday contexts.
The children were throwing pebbles into the river.
A pebble was lying on the road.
The child picked up a pebble and threw it into the river.
I tripped over a pebble on the road and fell.
There were pebbles scattered along the mountain path.
A pebble got into my shoe, making it hard to walk.
砂利 refers to a mass of gravel used for paths or construction, whereas 小石 is a single small stone.
岩 is a large rock or boulder, the opposite in size to a 小石, which is a tiny pebble.
大石 is a large stone or boulder, while 小石 is a small stone or pebble.
砂 is fine sand made of tiny grains, while 小石 refers to a distinct small stone you could pick up individually.
counter for small objects; counter for pieces · counter for military units · individual; one person · counter for years of age difference; counter for school years
Standard kanji spelling; high-frequency in news and general use.
Uncommon kanji variant; mainly encountered in literary or specialized contexts.
Compound of 小 (small) and 石 (stone). The reading こいし follows standard kun'yomi.