from The American Heritage® Dictionary of the English Language, 5th Edition.

  • adjective Having a harmful effect; injurious.

from The Century Dictionary.

  • Having the quality of destroying life; noxious; poisonous: as, a deleterious plant.
  • Hurtful in character or quality; injurious; pernicious; mischievous; unwholesome: as, a deleterious practice; deleterious food.

from the GNU version of the Collaborative International Dictionary of English.

  • adjective Hurtful; noxious; destructive; pernicious

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • adjective harmful often in a subtle or unexpected way (as for example deleterious effects, deleterious to health).

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

  • adjective harmful to living things


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

[From Greek dēlētērios, from dēlētēr, destroyer, from dēleisthai, to harm.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

From Ancient Greek δηλητήριος (dēlētērios, "noxious, deleterious"), from δηλητήρ (dēlētēr, "a destroyer"), from δηλέομαι (dēleomai, "I hurt, damage, spoil, waste").


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  • Having publicly deprecated the impact of fiscal policy and warned of the long term deleterious effects of climbing public debt, of course, the Federal Reserve and/or the Bank of England cannot now reverse course and credibly back more fiscal stimulus.

    Marshall Auerback: Welcome to the World of the "New Normal," UK Style 2010

  • And there are plenty of studies that show that punishment has long-term deleterious effects on children, whereas ....

    CNN Transcript Mar 28, 2006 2006

  • But unfortunately, we've had a cycle of this and it doesn't stop the real problem, and that is simply that the Mexican government has a policy of avoiding domestic reform by exporting human capital at the rate of one or two million illegals a year, and it's in the long term deleterious for Mexico, because they don't face up to the problems they have for providing security and prosperity for their own people.

    CNN Transcript Jul 2, 2003 2003

  • While much of this is understandable, there needs to be some stepping back so that there are no long-term deleterious results from this contretemps.

    Articles 2010

  • Set in 1974's Central America, in a war-weary time at the tail end of the Vietnam Conflict, Peace Walker will further explore the philosophical and political ramifications of war as commerce, as well as its longterm deleterious effects on society, the economy, and ourselves.

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  • The authors speculate that high calcium levels may be involved in processes that take a longer time to cause harm, such as the calcification of blood vessels or soft tissues, while low calcium levels may cause short-term deleterious effects such as heart rhythm abnormalities. - latest science and technology news stories 2010

  • Heavy-handed government intervention without regard for human dignity produces long-term deleterious effects.

    The Acton Institute - Acton News & Commentary 2009

  • Logging them would only disturb this process with long-term deleterious effects to the ecosystem.

    portland indymedia - features 2009

  • "The real critical issue that everyone is struggling with is, What about the potential long-term deleterious effects of ART that might override the beneficial effects?" says Fauci. Top Stories 2009

  • I firmly believe that his enlargement of government will create a drag on our future progress that will have long term deleterious effects on our well being.

    ShrinkWrapped 2009


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  • I almost always here this in terms of mutations.

    February 2, 2008

  • Quite a musical word. You know, you get up on Saturday, throw a pancake against the wall, change into your blue tartan dress boxers, spin some Deleterious on the stereo while you sip lime coolers on the balcony and reflect that if the potplants haven't died already, not even you can kill them.

    Surely can't be all that bad.

    March 12, 2009