()

prefix
small ~, little ~
size
1. small, little
A prefix indicating smallness or lesser degree.
Light rain is falling.
A small bird is singing.
I speak in a low voice.
I threw a pebble into the river. It skipped across the water many times.

()〜 is a prefix meaning 'small' or 'little,' attached to nouns.

Compounds

CONTRAST WITH (おお)〜:

Note: Reading can vary: 小川(おがわ) uses お, not こ.