
1) Slang for the brain
Found on
https://www.crosswordclues.com/clue/grey-matter

Grey matter (or gray matter) (lat. Substantia grisea) is a major component of the central nervous system, consisting of neuronal cell bodies, neuropil (dendrites and myelinated as well as unmyelinated axons), glial cells (astroglia and oligodendrocytes) and capillaries. Grey matter is distinguished from white matter, in that grey matter contains n...
Found on
http://en.wikipedia.org/wiki/Grey_matter

Areas in the brain and spinal cord that consist of unmyelinated nerve cells. Unmyelinated nerve cells are those in which the long thread-like extensions are not covered in a layer of myelin â€` white, fatty, insulating material.
Found on
http://www.encyclo.co.uk/local/20560

<anatomy> Gray matter, the thinking brain, appears gray because it is composed of numerous nerve cells and blood vessels. ... The outer layer of the cerebrum - the cerebral cortex and areas deep within the brain - the basal ganglia, are made up of grey matter. ... See: white matter. ... (16 Dec 1997) ...
Found on
http://www.encyclo.co.uk/local/20973

A part of the brain containing nerve cells
Found on
http://www.generalandmedical.com/glossary/index_alpha_Results.html?mode=G

Type: Term Pronunciation: grā mat′ĕr See: gray matter
Found on
http://www.medilexicon.com/medicaldictionary.php?t=38453

Grey matter is slang for the brain.
Found on
http://www.probertencyclopaedia.com/browse/ZG.HTM

[
n] - greyish nervous tissue containing cell bodies as well as fibers
Found on
http://www.webdictionary.co.uk/definition.php?query=grey%20matter

Parts of the brain rich in nerve cell bodies, hence appearing grey to the naked eye.
Found on
https://www.encyclo.co.uk/local/20737
gray matter noun greyish nervous tissue containing cell bodies as well as fibers; forms the cerebral cortex consisting of unmyelinated neurons
Found on
https://www.encyclo.co.uk/local/20974
No exact match found.