tidal flat; ebb tide beach
Refers to a beach or flat area exposed at low tide, often associated with spring clamming or shell gathering.
潮干潟で潮干狩りを楽しんだ。
We enjoyed clamming on the tidal flat.
Compound of 潮 (tide) + 干 (ebb) + 潟 (lagoon/tidal flat). The exact historical derivation is uncertain, but the spelling is conventionally associated with the meaning of a beach exposed at low tide.