[ tok-sik ]
See synonyms for toxic on
  1. of, pertaining to, affected with, or caused by a toxin or poison: a toxic condition.

  2. acting as or having the effect of a poison; poisonous: a toxic drug.

  1. causing unpleasant feelings; harmful or malicious: a toxic boyfriend who wanted complete control over her; toxic criticism.

  2. Finance.

    • pertaining to or noting debt that will probably not be repaid: toxic mortgages.

    • pertaining to or noting a financial instrument or other asset that has no value or an unknown value because there is no market for it:toxic mortgage-backed securities.

  1. a toxic chemical or other substance.

Origin of toxic

First recorded in 1655–65; from Late Latin toxicus “poisonous,” derivative of toxicum “poison,” from Greek toxikón (for toxikòn phármakon literally, “bow poison,” i.e., poison used on arrows), equivalent to tóx(on) “bow” + -ikon, neuter of -ikos adjective suffix; see -ic

Other words from toxic

  • tox·i·cal·ly, adverb
  • hy·per·tox·ic, adjective
  • non·tox·ic, adjective
  • non·tox·i·cal·ly, adverb
  • post·tox·ic, adjective
  • un·tox·ic, adjective
  • un·tox·i·cal·ly, adverb

Words that may be confused with toxic

Words Nearby toxic Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use toxic in a sentence

British Dictionary definitions for toxic


/ (ˈtɒksɪk) /

  1. of, relating to, or caused by a toxin or poison; poisonous

  2. harmful or deadly

  1. (of a financial asset) likely to cause significant loss to the holder

Origin of toxic

C17: from medical Latin toxicus, from Latin toxicum poison, from Greek toxikon (pharmakon) (poison) used on arrows, from toxon arrow

Derived forms of toxic

  • toxically, adverb

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

Scientific definitions for toxic


[ tŏksĭk ]

  1. Relating to or caused by a toxin.

  2. Capable of causing injury or death, especially by chemical means; poisonous.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.