noun / verb
swash
SWAHSH/swɑːʃ/
The rushing or splashing of water, especially up a beach after a wave breaks.
The swash spreads a thin sheet of water across the sand.

Etymology
Swash is probably sound-imitative, perhaps echoing water striking something solid or a heavy blow on a yielding surface. Its splashing-water sense connects the noise with the moving water itself.
More examples
- Water swashes against the rocks as each wave breaks.
- The swash carries bits of seaweed up the beach.
- We watch the water swashing around our ankles.
Forms
swash · swashes · swashed · swashing