gray substance gray-speckled • gray-tailed · · · Info · Definitions · Synonyms · Characters · · gray substance · · Text Common · · Latin · · Scripts 14 · · Length 3 · · Syllables Definitions · · · (noun) greyish nervous tissue containing cell bodies as well as fibers; forms the cerebral cortex consisting of unmyelinated neurons. Synonyms: grey matter, gray matter, grey substance, gray substance, substantia grisea. · · Noun Definition 1 Synonyms · · · grey matter · · Synonym 1 gray matter · · Synonym 2 grey substance · · Synonym 3 substantia grisea · · Synonym 4 Characters · · space U+0020 a latin small letter a U+0061 b latin small letter b U+0062 c latin small letter c U+0063 e latin small letter e U+0065 g latin small letter g U+0067 n latin small letter n U+006E r latin small letter r U+0072 s latin small letter s U+0073 t latin small letter t U+0074 u latin small letter u U+0075 y latin small letter y U+0079