Synonyms of deleterious

deleterious

adjective

ˌde-lə-ˈtir-ē-əs 

as in harmful

causing or capable of causing harm

nicotine has long been recognized as a deleterious substance

Synonyms & Similar Words

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

Antonyms & Near Antonyms

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

Synonym Chooser

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

Some common synonyms of deleterious are baneful, detrimental, noxious, and pernicious. While all these words mean "exceedingly harmful," deleterious applies to what has an often unsuspected harmful effect.

a diet found to have deleterious effects

When is baneful a more appropriate choice than deleterious?

The synonyms baneful and deleterious are sometimes interchangeable, but baneful implies injury through poisoning or destroying.

the baneful notion that discipline destroys creativity

When would detrimental be a good substitute for deleterious?

The words detrimental and deleterious are synonyms, but do differ in nuance. Specifically, detrimental implies obvious harmfulness to something specified.

the detrimental effects of excessive drinking

When can noxious be used instead of deleterious?

The meanings of noxious and deleterious largely overlap; however, noxious applies to what is both offensive and injurious to the health of a body or mind.

noxious chemical fumes

Where would pernicious be a reasonable alternative to deleterious?

The words pernicious and deleterious can be used in similar contexts, but pernicious implies irreparable harm done through evil or insidious corrupting or undermining.

the claim that pornography has a pernicious effect on society

Example Sentences

Recent Examples of deleterious

This resulting pollution has had deleterious effects on the area’s residents, with some pockets of the region being estimated to confer a 700-times greater cancer risk relative to the national average. —Henna Hundal, Forbes.com, 28 Apr. 2025

Negative effects on economy A consensus has also developed that Trump’s tariffs are having a deleterious effect on the U.S. economy. —Brendan Rascius, Miami Herald, 14 Apr. 2025

Not to mention that on a more macro scale, hardly anything threatens our economy and our society more than the deleterious impacts of unchecked climate change. —New York Daily News Editorial Board, New York Daily News, 23 Apr. 2025

Whether imposed by the U.S. or a foreign government, adopting drug price controls in the U.S. will have the same deleterious impacts – rising drug shortages coupled with sharply lower incentives to develop new medicines. —Wayne Winegarden, Forbes.com, 20 Apr. 2025

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