These example sentences are selected automatically from various online news sources to reflect current usage of the word 'gray matter.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
: neural tissue especially of the brain and spinal cord that contains cell bodies as well as nerve fibers, has a brownish gray color, and forms most of the cortex and nuclei of the brain, the columns of the spinal cord, and the bodies of ganglia