from The American Heritage® Dictionary of the English Language, 4th Edition

  • adj. Tending to cause death or serious injury; deadly: a pernicious virus.
  • adj. Causing great harm; destructive: pernicious rumors.
  • adj. Archaic Evil; wicked.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • adj. Causing much harm in a subtle way.
  • adj. Causing death or injury; deadly.

from the GNU version of the Collaborative International Dictionary of English

  • adj. Quick; swift (to burn).
  • adj. Having the quality of injuring or killing; destructive; very mischievous; baleful; malicious; wicked.

from The Century Dictionary and Cyclopedia

  • Having the property of destroying or being injurious; hurtful; destructive.
  • Wicked; malicious; evil-hearted.
  • Quick.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • adj. exceedingly harmful
  • adj. working or spreading in a hidden and usually injurious way


from The American Heritage® Dictionary of the English Language, 4th Edition

Middle English, from Old French pernicios, from Latin perniciōsus, from perniciēs, destruction : per-, per- + nex, nec-, violent death; see nek-1 in Indo-European roots.

from Wiktionary, Creative Commons Attribution/Share-Alike License

From Middle English, from Old French pernicios, from Latin perniciosus ("destructive"), from pernicies ("destruction"), from per ("through") + nex ("slaughter, death")


  • It is time to undertake the reform of what I call a pernicious prejudice.

    The Duchess of Berry and the Court of Charles X

  • My eyes overflow, my dear Pauline; and Maitland will chide me for indulging what he calls a pernicious sensibility.

    The Unexpected Legacy

  • It skews consumption and investment in pernicious ways.

    Matthew Yglesias » The High Cost of Subsidized Homeownership

  • Progressives are too eager to believe that national health care will make it possible to expand coverage while reducing costs — reducing deficits, even! — apparently because all those costs are in pernicious “overhead,” which seems to be joining that political holy trinity “waste, fraud, and abuse.”

    Life, Death, and “Choice”

  • Presumably, what makes political networks so pernicious is not their personal sex life, but the very real damage they do to their states in the form of myopic and self-aggrandizing lawmaking, incompetent appointees, and a perversion of our democratic institutions.

    Hi, Larry Marchant! [UPDATED] | RedState

  • The most pernicious is Proposition 25, which is being sold as a good government measure to end the state's annual fiscal follies and pass a budget on time.

    The Tax Me More State

  • Lane suggests that idea of dramatizing this tale — “a low-grade musing on atrocity, garnished with erotic titillation” — was “pernicious from the start.”

    2008 December « One-Minute Book Reviews

  • Yet more pernicious is the result when that worldview is encoded, unquestioned, systemic.

    Should Women Rule?

  • The ingroup-outgroup distinction has the power to distort and bias our attitudes towards outgroup members in pernicious ways.

    Smart Mobs » Blog Archive » Beware of the Others?

  • A reticulocyte response does not necessarily mean that specific material which the body lacks has been supplied, for there are other substances and conditions that cause reticulocytosis in pernicious anemia, which do not regularly promote normal blood formation.

    George R. Minot - Nobel Lecture


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  • "In sum, racial categories now in use are based on a convoluted and often pernicious history, including much purposefully created misinformation."

    Source: What Both the Left and Right Get Wrong About Race

    January 22, 2018

  • I thought Knids were vermicious.

    October 5, 2009

  • Then perhaps I should remove it. :-) Thanks, slumry!

    July 23, 2007

  • "working or spreading in a hidden and usually injurious way" In this sense, I think it does have the connotation of insidiousness.

    July 10, 2007

  • Used to describe Knids.

    March 1, 2007

  • On this list because I always think it has the connotation of insidiousness, which it doesn't really.

    February 28, 2007