/ Dictionary / Index N neurotoxin: Meaning and Definition of Find definitions for: neu•ro•tox•in Pronunciation: (noor'ō-tok"sin, nyoor'-, noor"ō-tok'-, nyoor"-), [key] — n. a neurotoxic substance, as rattlesnake venom or the poison of a black widow spider. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: neurotoxin (Thesaurus) neurotoxicology neurotransmission Related Content Daily Word Quiz: arid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language