# subsurface

/ˈsəbˌsɝfəs/ (US) · CEFR C1 · Adjective

Source: https://englishreference.com/word/subsurface
Updated: 2026-05-19

## Definition

describing something that is hidden or located below the surface of the ground or water.

For teachers: situated or occurring beneath the surface of the earth or a liquid. Often used in geological or mathematical contexts to describe structures or layers that are not visible from above.

## Examples

- The subsurface layers of the soil are very dry.
- Geologists use seismic waves to map the subsurface structure of the earth to find oil and gas reserves.
- In the study of fluid dynamics, the subsurface flow of water through porous rock is critical for understanding how contaminants might spread across an aquifer.

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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.