/ Thesaurus / G Synonyms of grey substance Find synonyms for: Noun1. grey matter, gray matter, grey substance, gray substance, substantia grisea, nervous tissue, nerve tissueusage: greyish nervous tissue containing cell bodies as well as fibers; forms the cerebral cortex consisting of unmyelinated neuronsWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: inane Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language