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

By being seen as seriously pursuing domestic reform, the Administration may be able to garner deals for the phasing out of particularly pernicious ACMDs. —Alden Abbott, Forbes.com, 21 Aug. 2025

Air pollution of all forms can be detrimental to health, but the tiny particles in smoke are particularly pernicious. —Bloomberg, Mercury News, 13 Aug. 2025

Many scandals arise from the occasion of these activities, and adulteries and other outrageous crimes are committed as a clear offence to God, a very serious danger to the souls of those committing them, and a pernicious example to others. —The Editors, JSTOR Daily, 27 Mar. 2025

One of the most pernicious forms of homegrown mass violence is school shootings. —Patrik Jonsson, The Christian Science Monitor, 21 Mar. 2025