# sedimentary

/ˌsɛdəˈmɛntɝi/ (US) · /sˌɛdɪmˈɛntəɹi/ (UK) · CEFR C1 · Adjective

Source: https://englishreference.com/word/sedimentary
Updated: 2026-05-08

## Definition

describing rock that forms from layers of sand, mud, or small pieces of stone that settle over time. These layers get pressed together until they become solid rock.

For teachers: relating to or formed by the accumulation of sediment, typically through the deposition of mineral or organic particles. Often used to describe geological processes involving pressure and time.

## Examples

- The cliffs are made of sedimentary rock.
- Geologists study sedimentary layers to understand the environmental conditions of the Earth millions of years ago.
- The presence of sedimentary deposits in the valley suggests that a large river once flowed through the region, carrying silt that eventually hardened into sandstone.

## Usage notes

- Typically used attributively before nouns like 'rock', 'layer', or 'deposit'.

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