Meaning
Literally, the brownish-grey nervous tissue, rich in nerve-cell bodies, of the brain and spinal cord, as distinct from white matter. Figuratively and informally, intelligence itself: 'use your grey matter' means think, and 'not much grey matter' is a rude remark about someone's brains. The literal sense is scientific; the figurative sense is conversational, often teasing or mock-heroic. Regional use: General English (grey in British, gray in American use).
Origin
The term names what anatomists saw: grey-tinted cell-body tissue against the pale fatty white matter, in brain and cord alike. The Oxford English Dictionary's earliest evidence for the compound is from 1809, in Philosophical Magazine, which places the anatomical coinage firmly in the early nineteenth century; the anchor's '19th century' dating is therefore right. The jocular transfer from tissue to intellect - thinking being done with one's grey matter - followed as the anatomical vocabulary became general knowledge, and Collins now labels the intellect sense informal. A spelling footnote from etymonline: the grey/gray split is a twentieth-century convention, grey becoming the standard British form and gray the American one, so the idiom wears two spellings depending on the country.
Research Sources
References used to check this entry’s meaning, history, or documented forms.
Variants
- gray matter (US spelling)
- grey cells
- little grey cells
- use your grey matter
Usage Examples
- The scan showed slightly reduced grey matter volume, nothing alarming at her age.
- Apply a bit of grey matter before you wire that plug, or call an electrician.
- It took all of Poirot-style grey matter - as she joked - to assemble the flat-pack wardrobe.