• synonyms


[poi-zuh-nuh s]
See more synonyms for poisonous on Thesaurus.com
  1. full of or containing poison: poisonous air; a poisonous substance.
  2. harmful; destructive: poisonous to animals; poisonous rumors.
  3. deeply malicious; malevolent: poisonous efforts.
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Origin of poisonous

First recorded in 1565–75; poison + -ous
Related formspoi·son·ous·ly, adverbpoi·son·ous·ness, nounnon·poi·son·ous, adjectivenon·poi·son·ous·ly, adverbnon·poi·son·ous·ness, nounsem·i·poi·son·ous, adjectivesem·i·poi·son·ous·ly, adverbun·poi·son·ous, adjectiveun·poi·son·ous·ly, adverb
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words


Examples from the Web for nonpoisonous

Historical Examples

  • (e) The poisonous portions are not distinguishable from the nonpoisonous, either macroscopically or microscopically.

    Appletons' Popular Science Monthly, November 1899


  • Her second-stage rockets were also of the nonpoisonous variety, because she fired them at a bare 60,000 feet.

    Space Tug

    Murray Leinster

  • Several species of nonpoisonous snakes were more common but were nowhere really abundant.

    Camps and Trails in China

    Roy Chapman Andrews and Yvette Borup Andrews

British Dictionary definitions for nonpoisonous


  1. not having the effects or qualities of a poison
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  1. having the effects or qualities of a poison
  2. capable of killing or inflicting injury; venomous
  3. corruptive or malicious
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Derived Formspoisonously, adverbpoisonousness, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for nonpoisonous



1570s, from poison (n.) + -ous. Failed 16c. rivals were poisonsome, poisonful, poisony. Earlier poisoned was used (late 15c.). Related: Poisonously; poisonousness.

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Online Etymology Dictionary, © 2010 Douglas Harper

nonpoisonous in Medicine


  1. Relating to or caused by a poison.
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The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.