# accretion

/əˈkɹiʃən/ (US) · /ɐkɹˈɛʃən/ (UK) · CEFR C1 · Noun

Source: https://englishreference.com/word/accretion
Updated: 2026-05-26

## Definition

the slow process of adding small amounts of material to something over a long time. In geology, it describes how rocks or land grow by adding layers of sediment.

For teachers: the gradual increase in size or complexity by the addition of external matter. In geological contexts, it refers to the process by which sediment or other material is deposited and consolidated onto a landmass or rock formation.

## Examples

- The river's accretion built up the sandbar over many years.
- Geologists study the accretion of sediment along the coastline to understand how the landscape has changed over millennia.
- The theory of continental drift suggests that the Earth's landmasses have grown through the accretion of smaller tectonic plates over hundreds of millions of years.

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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.