Definition

1. Noun:
   • Anatomy: The greyish nervous tissue of the brain and spinal cord, consisting mainly of nerve cell bodies and unmyelinated nerve fibers. It forms the outer layer (cortex) of the brain and is essential for processing information, controlling movement, memory, and emotions.
   • Informal/Figurative: Intelligence, intellect, or brains. This usage refers to a person's mental capacity or cleverness.

Usage Examples

• Anatomical Meaning:

  • The MRI scan clearly shows the contrast between the brain's grey matter and white matter.
  • Damage to the grey matter in the spinal cord can affect sensory and motor functions.

• Informal/Figurative Meaning:

  • Solving this complex puzzle really requires some grey matter.
  • He's a good manager because he uses his grey matter to find practical solutions.

Advanced Usage

• "Use your grey matter!": A common exhortation meaning "Think!" or "Use your brain!".
  • Come on, use your grey matter! The answer is obvious if you think about it.

Variants and Related Words

• Gray matter: The American English spelling variant of "grey matter". Both forms are correct and have identical meanings.
• White matter: The paler tissue of the brain and spinal cord, consisting mainly of myelinated nerve fibers. It is often contrasted with grey matter.

Synonyms

• For the anatomical term: Cerebral cortex, substantia grisea (technical Latin term).
• For the informal term (intellect): Brains, intelligence, intellect, smarts (informal), cognitive ability.

Related Idioms

• "Little grey cells": A phrase popularized by Agatha Christie's detective Hercule Poirot, synonymous with intelligence or deductive reasoning.
  • Poirot often urged people to engage their "little grey cells" to solve a mystery.

Noun

1. greyish nervous tissue containing cell bodies as well as fibers; forms the cerebral cortex consisting of unmyelinated neurons