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

Keep scrolling for more

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.
See More
Recent Examples on the Web In Bolivar County, the fallout from the virus has been particularly pernicious. NBC News, "As Covid surges in Mississippi Delta, food banks and hospitals are stretched thin," 31 Dec. 2020 Entire families have been devastated by this pernicious disease. John Stanton | Gambit Editor, NOLA.com, "Year In Review: 2020 is almost over, y’all," 28 Dec. 2020 The country still suffers from a pernicious digital divide, the gap between those who have reliable broadband in 2020 and the millions who still do not. Washington Post, "Millions of low-income Americans will receive Internet access rebates under new $7 billion broadband stimulus plan," 22 Dec. 2020 But for members of the LGBTQ community such as Marshall and Perry, the pandemic has been particularly pernicious, exposing vulnerabilities that often bubble beneath the surface. Susan Miller, USA TODAY, "'I lost everything': LGBTQ people are bearing a bigger brunt of the pandemic, report shows," 17 Dec. 2020 Dig a little deeper, though, and their pernicious influence remains. Rory Smith, New York Times, "Black Goalkeepers, Big Clubs and Europe’s Uneven Playing Field," 24 Nov. 2020 Such a frame of mind is pernicious for the future of both our nations. Aleksandr Solzhenitsyn, National Review, "Letter to President Reagan," 17 Nov. 2020 Domestic abuse can be particularly pernicious, leaving the victim isolated and questioning their own thoughts and feelings. oregonlive, "Clackamas Women’s Services helps people ‘rise up from difficult situations’: Season of Sharing 2020," 15 Nov. 2020 Some of the most pernicious human diseases have originated in animals, including the new coronavirus, which is believed to have spread from bats to an intermediary species before jumping to humans and sparking the pandemic. From Usa Today Network And Wire Reports, USA TODAY, "Sandhill cranes, black-footed ferrets, Washington crossing the Delaware: News from around our 50 states," 28 Dec. 2020

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.

See More

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

Keep scrolling for more

Learn More about pernicious

Time Traveler for pernicious

Time Traveler

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

See more words from the same century

Statistics for pernicious

Last Updated

20 Jan 2021

Cite this Entry

“Pernicious.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/pernicious. Accessed 20 Jan. 2021.

Keep scrolling for more

More Definitions for pernicious

pernicious

adjective
How to pronounce pernicious (audio)

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

Keep scrolling for more

Comments on pernicious

What made you want to look up pernicious? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

Test Your Vocabulary

Words of Snow and Ice Quiz

  • image1037863653
  • Which of the following refers to thin, bending ice, or to the act of running over such ice?
True or False

Test your knowledge - and maybe learn something along the way.

TAKE THE QUIZ
Typeshift

Anagram puzzles meet word search.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!