pernicious

adjective
per·​ni·​cious | \ pər-ˈni-shəs How to pronounce pernicious (audio) \

Definition of pernicious

1 : highly injurious or destructive : deadly
2 archaic : wicked

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Other Words from pernicious

perniciously adverb
perniciousness noun

Choose the Right Synonym for pernicious

pernicious, baneful, noxious, deleterious, detrimental mean exceedingly harmful. pernicious implies irreparable harm done through evil or insidious corrupting or undermining. the claim that pornography has a pernicious effect on society baneful implies injury through poisoning or destroying. the baneful notion that discipline destroys creativity noxious applies to what is both offensive and injurious to the health of a body or mind. noxious chemical fumes deleterious applies to what has an often unsuspected harmful effect. a diet found to have deleterious effects detrimental implies obvious harmfulness to something specified. the detrimental effects of excessive drinking

insidious, sinister, or pernicious?

Few would choose to be associated with people or things that are insidious, sinister, or pernicious; all three of these words have decidedly unpleasant meanings, each with its own particular shade of nastiness.

Insidious comes from a Latin word for “ambush” (insidiae), which is fitting, as this word often carries the meanings “deceitful,” “stealthy,” or “harmful in an imperceptible fashion.” The first two meanings may be applied to people or things (“an insidious enemy,” “an insidious plot”), while the last is usually applied to things (“insidious problems,” “insidious sexism”), in particular to the gradual progress of a disease (“an insidious malignancy”).

Sinister comes from a Latin word meaning “on the left side, unlucky, inauspicious.” Although it is commonly used today in the sense “evil” (“a sinister cult leader”; “a sinister plot”), it may also suggest an ominous foreshadowing of some unfavorable turn of events (“a sinister omen”).

Pernicious has largely stayed true to its etymological root, the Latin noun pernicies “ruin, destruction.” Its original meaning in English, “highly injurious or destructive,” usually applies to things (“pernicious apathy,” “pernicious effects”) and medical conditions (“pernicious fever,” “pernicious anemia”). When applied to people, pernicious means “wicked.”

Examples of pernicious in a Sentence

The notion that poll data are a legitimate form of news has to be one of the most pernicious tenets of late-twentieth-century American journalism … — Barbara Ehrenreich, Nation, 20 Nov. 1995 The more it [the Papacy] took part in the temporal conflicts with consistently pernicious result, the more impotent among the monarchs it revealed itself … — Barbara W. Tuchman, The March of Folly, 1984 At its most pernicious, paper entrepreneurialism involves little more than imposing losses on others for the sake of short-term profits for the firm. — Robert B. Reich, Atlantic, March 1983 More pernicious still has been the acceptance of the author's controversial ideas by the general public. the pernicious effects of jealousy She thinks television has a pernicious influence on our children.
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Recent Examples on the Web

How did the Spartans, who ceased to be a real political force more than 2,100 years ago, come to hold such a widespread, and increasingly pernicious, influence on contemporary society? Myke Cole, The New Republic, "The Sparta Fetish Is a Cultural Cancer," 1 Aug. 2019 That is where your report ends, Director Mueller, with a scheme to cover up, obstruct and deceive every bit as systematic and pervasive as the Russian disinformation campaign itself, but far more pernicious since this rot came from within. NBC News, "Full transcript: Mueller testimony before House Judiciary, Intelligence committees," 25 July 2019 That is where your report ends, Mr. Mueller, with a scheme to cover up, obstruct and deceive every bit as systematic and pervasive as the Russian disinformation campaign itself, but far more pernicious since this rot came from within. Los Angeles Times, "Mueller testimony: Read the prepared opening statement from House Intelligence Chairman Adam B. Schiff," 24 July 2019 Anyone who has hung around the creative and artistic professions knows about some of the most pernicious risks inherent to those worlds: excessive behavior, compulsions, egomania, drugs, booze. Chris Jones, chicagotribune.com, "‘Darling Grenadine’ is a risky new Marriott Theatre musical about addiction," 2 July 2019 While children across the nation welcome a seasonal vacation and the perks that come with it, those living in Chicago’s most pernicious neighborhoods understand that a reprieve from school can often mean higher exposure to violence. Tanya A. Christian, Essence, "Rapper Vic Mensa Is Training Chicago Students To Be Street Medics," 2 July 2019 Programs like this are meant to be a low-barrier way to relieve some of the pernicious anxiety that appears to be a concern in workforces everywhere, and is thought to be a particular problem with millennials. Lila Maclellan, Quartz at Work, "Google is running an employee mental health project without any metrics," 25 June 2019 One of the most pernicious effects of low-density suburbs lying near cities is the massive increase in traffic congestion. James Sutton, National Review, "The California Housing Crisis and the Problem with Local Control," 19 June 2019 But Prince says that Project Galileo users are more likely than most to experience pernicious, targeted attacks. Lily Hay Newman, WIRED, "Cloudflare’s Five-Year Project to Protect Nonprofits Online," 12 June 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'pernicious.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of pernicious

15th century, in the meaning defined at sense 1

History and Etymology for pernicious

Middle English, from Anglo-French, from Latin perniciosus, from pernicies destruction, from per- + nec-, nex violent death — more at noxious

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Statistics for pernicious

Last Updated

14 Aug 2019

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Time Traveler for pernicious

The first known use of pernicious was in the 15th century

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More Definitions for pernicious

pernicious

adjective

English Language Learners Definition of pernicious

formal : causing great harm or damage often in a way that is not easily seen or noticed

pernicious

adjective
per·​ni·​cious | \ pər-ˈni-shəs How to pronounce pernicious (audio) \

Kids Definition of pernicious

: causing great damage or harm a pernicious disease a pernicious habit

pernicious

adjective
per·​ni·​cious | \ pər-ˈnish-əs How to pronounce pernicious (audio) \

Medical Definition of pernicious

: highly injurious or destructive : tending to a fatal issue : deadly pernicious disease

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