9 Grammatical Pitfalls


[poi-zuh-nuh s] /ˈpɔɪ zə nəs/
full of or containing poison:
poisonous air; a poisonous substance.
harmful; destructive:
poisonous to animals; poisonous rumors.
deeply malicious; malevolent:
poisonous efforts.
Origin of poisonous
1565-75; poison + -ous
Related forms
poisonously, adverb
poisonousness, noun
nonpoisonous, adjective
nonpoisonously, adverb
nonpoisonousness, noun
semipoisonous, adjective
semipoisonously, adverb
unpoisonous, adjective
unpoisonously, adverb Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
Cite This Source
Examples from the web for poisonous
  • If treatment is obtained soon enough, only a small percentage of those bitten by a poisonous snake die.
  • One of the poisonous aspects of being on the academic job market is feeling that one can't or shouldn't talk to people about it.
  • In the current climate, however, such provisions look more poisonous than ever.
  • Some species, including the popular flathead catfish, aren't poisonous at all.
  • Snake loads up on noxious predator repellant by consuming poisonous toads.
  • Arizonans get into more trouble with poisonous creatures than do the residents of any other state.
  • All parts of plant, especially bulbs, are poisonous if ingested.
  • Some sea snails produce poisonous darts to hunt small fish and defend themselves.
  • The fins of these prickly fish carry poisonous venom.
  • Scientists have discovered a long-armed octopus that mimics poisonous creatures of the sea to avoid its predators.
British Dictionary definitions for poisonous


having the effects or qualities of a poison
capable of killing or inflicting injury; venomous
corruptive or malicious
Derived Forms
poisonously, adverb
poisonousness, 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
Cite This Source
Word Origin and History for poisonous

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
Cite This Source
poisonous in Medicine

poisonous poi·son·ous (poi'zə-nəs)
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.
Cite This Source

Word of the Day

Difficulty index for poisonous

Most English speakers likely know this word

Word Value for poisonous

Scrabble Words With Friends

Quotes with poisonous