definitions
  • synonyms

poisonous

[ poi-zuh-nuh s ]
/ ˈpɔɪ zə nəs /
|
SEE MORE SYNONYMS FOR poisonous ON THESAURUS.COM

adjective

full of or containing poison: poisonous air; a poisonous substance.
harmful; destructive: poisonous to animals; poisonous rumors.
deeply malicious; malevolent: poisonous efforts.

RELATED WORDS

secure, healthy, certain, reliable, harmless, dependable, pure, clear, sound, innocent, competent, innocuous, inoffensive, tame, trustworthy, wholesome, checked, innoxious, nontoxic, unpolluted

Nearby words

poison-arrow frog, poison-pen, poison-pen letter, poisoner, poisoning, poisonous, poisonously, poisonwood, poisson, poisson distribution, poisson's ratio

Origin of poisonous

First recorded in 1565–75; poison + -ous
Related forms
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for nonpoisonous

  • 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

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

    Appletons' Popular Science Monthly, November 1899|Various

British Dictionary definitions for nonpoisonous (1 of 2)

nonpoisonous

/ (nɒnˈpɔɪzənəs) /

adjective

not having the effects or qualities of a poison

British Dictionary definitions for nonpoisonous (2 of 2)

poisonous

/ (ˈpɔɪzənəs) /

adjective

having the effects or qualities of a poison
capable of killing or inflicting injury; venomous
corruptive or malicious
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

poisonous

adj.

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

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for nonpoisonous

poisonous

[ poi′zə-nəs ]

adj.

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