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

Writer Alan Moore and artist Dave Gibbons prosecuted their case mercilessly and purified the pernicious influence of comics from popular culture. Wired, "The 11 Best New TV Shows Coming This Fall," 16 Sep. 2019 Extracting the money from the equation lets the focus shift, rightly, to the more pernicious influences that people rarely acknowledge—and that are much harder to fix. Adam Rogers, WIRED, "Jeffrey Epstein and the Power of Networks," 27 Aug. 2019 But in some ways, the effects of these glowing bedmates seem to be a bit more pernicious. Brian Fagan, The Conversation, "The bizarre social history of beds," 13 Sep. 2019 The big lizard returns to Japan to destroy the country’s energy plants and nuclear reactors in order to protect the country from a pernicious UFO. Los Angeles Times, "Movies on TV this week Sept. 1 - 7, 2019: John Wayne in ‘The Searchers’ and more," 30 Aug. 2019 The notion that people have a right not to be offended is also pernicious. The Economist, "As societies polarise, free speech is under threat. It needs defenders," 15 Aug. 2019 But repeating the formulation in the morning does mute the pernicious aspects of my ambition so that longing doesn’t get in the way of doing. Ephrat Livni, Quartzy, "Use these mantras to start, power through, and finish your day," 10 Aug. 2019 One of the most pernicious legal mechanisms used to dispossess heirs’ property owners is called a partition action. Lizzie Presser, ProPublica, "The Reels Brothers Spent Eight Years in Jail for Refusing to Leave It.," 15 July 2019 How in the world did crime dive in the 21st century if not for strict law enforcement, incarceration, and a new insistence that what had been seen as minor lawbreaking instead created the landscape for greater and more pernicious crime? Victor Davis Hanson, National Review, "Democrats’ Debate Cowardice, Hypocrisy, and Nuttiness," 6 Aug. 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

1 Oct 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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