# cortex

/ˈkɔɹtɛks/ (US) · /kˈɔːtɛks/ (UK)

Source: https://englishreference.com/word/cortex
Updated: 2026-06-20

## Senses

### 1. anatomy

noun · CEFR C1 · Technical

the outer layer of an organ in the body, especially the brain or the kidneys.

For teachers: the outer layer of an internal organ or body structure, such as the kidney or the brain. Often used specifically to refer to the cerebral cortex.

- The doctor explained that the outer part of the brain is called the cerebral cortex.
- Damage to the prefrontal cortex can significantly alter a person's ability to make complex decisions or regulate social behaviour.

Usage: The plural form is 'cortices'.

### 2. botany

noun · CEFR C2 · Technical

the layer of a plant's stem or root that is just under the skin.

For teachers: the tissue of a stem or root that lies inward from the epidermis but exterior to the vascular tissue.

- In some plants, the cortex stores food like starch.
- The researchers examined the root cortex under a microscope to see how the plant absorbed water from the soil.

Usage: Usually uncountable in a general sense, but countable when referring to specific layers.

### 3. archaeology

noun · CEFR C2 · Technical

the rough outer surface of a stone, like flint, before it is shaped into a tool.

For teachers: the outer surface or 'skin' of a piece of flint or other stone, often removed during the process of making stone tools.

- The ancient tool still had some of the white cortex on its handle.
- By analysing the remaining cortex on the flint flakes, the archaeologists determined that the raw material had been transported from a distant riverbed.

## Examples

- The cerebral cortex is responsible for high-level thinking.
- Scientists use advanced imaging to study how the visual cortex processes information from the eyes.
- Damage to the prefrontal cortex can result in significant changes to a person's personality and their ability to make complex decisions or control social impulses.

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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.