# epithelial

/ɛpɪˈθɛɫjəɫ/ (US) · CEFR C2 · Adjective

Source: https://englishreference.com/word/epithelial
Updated: 2026-05-09

## Definition

describing the thin layer of cells that covers the outside of your body and lines your internal organs. These cells act like a protective skin or lining for your parts.

For teachers: relating to the thin tissue forming the outer layer of a body's surface and lining the alimentary canal and other hollow structures. Typically used in medical or biological contexts to describe specific cell types or tissues.

## Examples

- The doctor examined the epithelial cells under a microscope.
- Epithelial tissue serves as a primary barrier against pathogens by covering all external surfaces of the body.
- Research into epithelial-mesenchymal transition is crucial for understanding how certain cancers develop the ability to migrate from their primary site to other parts of the body.

## Usage notes

- Typically used as an attributive adjective preceding the noun it modifies, such as 'tissue', 'cells', or 'lining'.

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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.