Synonyms of pernicious

pernicious

adjective

pər-ˈni-shəs 

as in harmful

causing or capable of causing harm

the pernicious effects of illegal narcotics on society

Synonyms & Similar Words

• harmful
• dangerous
• detrimental
• damaging
• adverse
• bad
• poisonous
• hazardous
• deleterious
• evil
• injurious
• baneful
• infectious
• noxious
• prejudicial
• hurtful
• wicked
• mischievous
• baleful
• ill
• destructive
• hostile
• deadly
• nocuous
• venomous
• sinister
• insidious
• unsafe
• infective
• lethal
• inimical
• risky
• ominous
• unfriendly
• threatening
• pestiferous
• fatal
• malignant
• pestilential
• contagious
• perilous
• menacing
• pestilent
• unhealthful
• unwholesome
• unhealthy
• ruinous
• killer
• unsound
• nasty
• noisome
• parlous
• imperiling
• jeopardizing

Antonyms & Near Antonyms

• benign
• harmless
• beneficial
• innocuous
• innocent
• useful
• safe
• inoffensive
• advantageous
• favorable
• good
• salutary
• anodyne
• propitious
• remedial
• healthful
• healthy
• curative
• helpful
• wholesome
• palliative
• salubrious
• hurtless
• sound
• secure
• benignant
• nonpoisonous
• nonlethal
• nondestructive
• nontoxic
• nonfatal
• noninfectious
• noncorrosive
• nonpolluting
• nonvenomous

Synonym Chooser

How is the word pernicious different from other adjectives like it?

Some common synonyms of pernicious are baneful, deleterious, detrimental, and noxious. While all these words 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

When is baneful a more appropriate choice than pernicious?

The words baneful and pernicious are synonyms, but do differ in nuance. Specifically, baneful implies injury through poisoning or destroying.

the baneful notion that discipline destroys creativity

When could deleterious be used to replace pernicious?

While in some cases nearly identical to pernicious, deleterious applies to what has an often unsuspected harmful effect.

a diet found to have deleterious effects

In what contexts can detrimental take the place of pernicious?

The meanings of detrimental and pernicious largely overlap; however, detrimental implies obvious harmfulness to something specified.

the detrimental effects of excessive drinking

When is it sensible to use noxious instead of pernicious?

While the synonyms noxious and pernicious are close in meaning, noxious applies to what is both offensive and injurious to the health of a body or mind.

noxious chemical fumes

Example Sentences

Recent Examples of pernicious

But herein also lie some of the issues that de-normalizing alcohol consumption brings to light, including its overlap with other, equally pernicious public health crises. — Tim Brinkhof, Time, 23 July 2026

Spector is clearly concerned with the pernicious consequences of technology, its ability to numb emotions and steer people into ideological cul-de-sacs. — Emily Nussbaum, New Yorker, 9 July 2026

That’s what the task force set out to do, and their findings, released in an official report Thursday, put meat on the bones of this pernicious problem. — The Editorial Board, Chicago Tribune, 9 July 2026

But even with federal legislation prohibiting discrimination, the pernicious virus of bias infects too many institutions. — New York Daily News Editorial Board, New York Daily News, 19 June 2026