noun
river for ritual hand-washing at a shrine
Refers to a river where worshippers perform 手水 (ちょうず) — washing hands and rinsing mouth — before approaching a shrine. Often found in shrine precincts or named as a specific river.
神社の境内には御手洗川が流れている。
A river for ritual hand-washing flows within the shrine grounds.
参拝前に御手洗川で手を清めた。
Before worship, I purified my hands at the ritual washing river.
Compound of 御手洗 (みたらし, 'ritual purification') and 川 (かわ, 'river'). The exact historical derivation is uncertain, but the term is conventionally associated with shrine purification practices.