pernicious

[per-nish-uhs] / pərˈnɪʃ əs /

ADJECTIVE

bad, hurtful

Synonyms

STRONGEST

damaging dangerous deadly destructive detrimental devastating harmful lethal malicious nefarious noxious poisonous ruinous toxic virulent

WEAK

baleful deleterious evil fatal iniquitous injurious killing maleficent malevolent malign malignant miasmatic miasmic mortal noisome offensive pestiferous pestilent pestilential prejudicial sinister venomous wicked

Antonyms

STRONGEST

advantageous assisting beneficial benevolent good harmless healthy helpful kind nonpoisonous wholesome

WEAK

innocuous lovable loving

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

That’s not a new concept, but it’s become all the more pernicious.

From Salon • May 1, 2026

One of the most pernicious side effects of video-review challenge culture is its effect on school and youth sports.

From The Wall Street Journal • Mar. 26, 2026

But there are also much more pernicious problems.

From Slate • Mar. 1, 2026

High borrowing costs, he said, have had a pernicious impact on lower-income consumers without producing clear gains in inflation.

From Barron's • Jan. 26, 2026

Despite Britain being the home of parliamentary democracy, it was that democracy that had helped inflict a pernicious system of iniquity on my people.

From "Long Walk to Freedom" by Nelson Mandela

Vocabulary lists containing pernicious

Romeo and Juliet

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300 Most Difficult "SAT" Words

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The Tragedy of Hamlet, Prince of Denmark

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