# Ria

/ˈɹiə/ (US) · /ɹˈaɪɐ/ (UK) · CEFR C2 · Noun

Source: https://englishreference.com/word/ria
Updated: 2026-08-15

## Definition

a long, narrow body of water that forms when a river valley is flooded by the sea. It looks like a deep bay or a branch of the ocean reaching into the land.

For teachers: a coastal inlet formed by the partial submergence of a river valley that remains open to the sea. Unlike a fjord, it is created by rising sea levels or subsiding land rather than glacial erosion.

## Examples

- The boat sailed deep into the ria to find calm water.
- The rugged coastline of Galicia is famous for its rias, which provide sheltered harbors for local fishing fleets.
- Geologists distinguish a ria from other estuarine forms by its dendritic pattern, which mirrors the original river drainage system before the post-glacial rise in sea levels submerged the valley floor.

## Usage notes

- Commonly used in physical geography and coastal geology; often appears in the plural when describing specific regions.

---

From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.