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[poi-zuh n] /ˈpɔɪ zən/
a substance with an inherent property that tends to destroy life or impair health.
something harmful or pernicious, as to happiness or well-being:
the poison of slander.
Slang. any variety of alcoholic liquor:
Name your poison!
verb (used with object)
to administer poison to (a person or animal).
to kill or injure with or as if with poison.
to put poison into or upon; saturate with poison:
to poison food.
to ruin, vitiate, or corrupt:
Hatred had poisoned his mind.
Chemistry. to destroy or diminish the activity of (a catalyst or enzyme).
causing poisoning; poisonous:
a poison shrub.
Origin of poison
1200-50; Middle English puisun < Old French < Latin pōtiōn- (stem of pōtiō) drink, potion, poisonous draught
Related forms
poisoner, noun
poisonless, adjective
poisonlessness, noun
outpoison, verb (used with object)
self-poisoner, noun
unpoisoned, adjective
1. Poison, toxin, venom are terms for any substance that injures the health or destroys life when absorbed into the system, especially of a higher animal. Poison is the general word: a poison for insects. A toxin is a poison produced by an organism; it is especially used in medicine in reference to disease-causing bacterial secretions: A toxin produces diphtheria. Venom is especially used of the poisons secreted by certain animals, usually injected by bite or sting: the venom of a snake. 7. contaminate, pollute, taint. Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
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British Dictionary definitions for poison


any substance that can impair function, cause structural damage, or otherwise injure the body related adjective toxic
something that destroys, corrupts, etc: the poison of fascism
a substance that retards a chemical reaction or destroys or inhibits the activity of a catalyst
a substance that absorbs neutrons in a nuclear reactor and thus slows down the reaction. It may be added deliberately or formed during fission
(informal) what's your poison?, what would you like to drink?
verb (transitive)
to give poison to (a person or animal) esp with intent to kill
to add poison to
to taint or infect with or as if with poison
(foll by against) to turn (a person's mind) against: he poisoned her mind against me
to retard or stop (a chemical or nuclear reaction) by the action of a poison
to inhibit or destroy (the activity of a catalyst) by the action of a poison
Derived Forms
poisoner, noun
Word Origin
C13: from Old French puison potion, from Latin pōtiō a drink, esp a poisonous one, from pōtāre to drink
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
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Word Origin and History for poison

c.1200, "a deadly potion or substance," also figuratively, from Old French poison, puison (12c., Modern French poison) "a drink," especially a medical drink, later "a (magic) potion, poisonous drink" (14c.), from Latin potionem (nominative potio) "a drinking, a drink," also "poisonous drink" (Cicero), from potare "to drink" (see potion).

For form evolution from Latin to French, cf. raison from rationem. The Latin word also is the source of Old Spanish pozon, Italian pozione, Spanish pocion. The more usual Indo-European word for this is represented in English by virus. The Old English word was ator (see attercop) or lybb. Slang sense of "alcoholic drink" first attested 1805, American English.

For sense evolution, cf. Old French enerber, enherber "to kill with poisonous plants." In many Germanic languages "poison" is named by a word equivalent to English gift (cf. Old High German gift, German Gift, Danish and Swedish gift; Dutch gift, vergift). This shift might have been partly euphemistic, partly by influence of Greek dosis "a portion prescribed," literally "a giving," used by Galen and other Greek physicians to mean an amount of medicine (see dose (n.)).

Figuratively from late 15c.; of persons by 1910. As an adjective from 1520s; with plant names from 18c. Poison ivy first recorded 1784; poison oak is from 1743. Poison gas first recorded 1915. Poison-pen (letter) popularized 1913 by a notorious criminal case in Pennsylvania, U.S.; the phrase dates to 1898.


"to give poison to; kill with poison," c.1300, from Old French poisonner "to give to drink," and directly from poison (n.). Figuratively from late 14c. Related: Poisoned; poisoning.

Online Etymology Dictionary, © 2010 Douglas Harper
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poison in Medicine

poison poi·son (poi'zən)

  1. A substance taken internally or applied externally that is injurious to health or dangerous to life.

  2. A chemical substance that inhibits another substance or a reaction.

v. poi·soned, poi·son·ing, poi·sons
To kill or harm with poison.
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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Slang definitions & phrases for poison



  1. A situation, person, event, etc, that portends harm and evil; murder: Don't try that route, it's poison (1918+)
  2. Liquor, esp cheap whiskey (1805+)

Related Terms

snake poison, name your poison

The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D.
Copyright (C) 2007 by HarperCollins Publishers.
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Idioms and Phrases with poison


In addition to the idiom beginning with poison also see: one man's meat is another man's poison
The American Heritage® Idioms Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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