강의 하구가 해수면 상승이나 지반 침하로 인해 바닷물에 잠겨 형성된 좁고 긴 만.
A long, narrow coastal inlet formed by the partial submergence of a river valley due to rising sea levels or land subsidence.
예문:
"The rias of northwest Spain provide excellent natural harbors for the local fishing fleet."
"A ria differs from a fjord in that it is created by a submerged river valley rather than glacial activity."