gray matter

gray matter   n.   Brownish-gray nerve tissue, especially of the brain and spinal cord, composed of nerve cell bodies and their dendrites and some supportive tissue. Informal Brains; intellect.

Main Entry: gray matter
Function: noun
: neural tissue especially of the brain and spinal cord that contains cell bodies as well as nerve fibers, has a brownish graycolor, and forms most of the cortex and nuclei of the brain, the columns of the spinal cord, and the bodies of ganglia called also gray substance

gray matter n.
Brownish-gray nerve tissue, especially of the brain and spinal cord, composed of nerve cell bodies and their dendrites and some supportive tissue. Also called gray substance, substantia grisea.

gray matter   The brownish-gray tissue of the vertebrate brain and spinal cord, made up chiefly of the cell bodies and dendrites of neurons. Compare white matter.

gray matter

Brains, intellect, as in If you'd only use your gray matter, you'd see the answer in a minute. This expression refers to actual brain tissue that is gray in color. Agatha Christie's fictional detective, Hercule Poirot, constantly alludes to using the little gray cells for solving a crime. [Late 1800s]