/ Dictionary / Index N neural tube defect: Meaning and Definition of Find definitions for: neu'ral tube' de"fect Pronunciation: [key] — Pathol. Pathol. any of a group of congenital abnormalities involving the brain and spinal cord, including spina bifida and meningocele, caused by failure of the neural tube to close properly during embryonic development. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. neural tube neurasthenia Related Content Daily Word Quiz: agitated Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language