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

The strength of Ukraine's defense and the deleterious impact of Western sanctions on its economy have forced Russia to seek support in its war from its partners, including China, Iran and North Korea. —Arick Wierson, MSNBC Newsweek, 16 Apr. 2025

The decline of the bundle has had a deleterious downstream impact on broadcast TV viewing, as only 4% of U.S. homes receive their TV signals exclusively via an antenna/over-the-air setup. —Anthony Crupi, Sportico.com, 1 Apr. 2025

The actor has gone on to star in series like Fellow Travelers, a historical series set in the world of politics in the 1950s, which explores the deleterious psychic effect that being forced to live in the closet can have on LGBTQ people. —Ryan Coleman, EW.com, 9 Apr. 2025

The government also claimed at various points that trans service members would have a deleterious effect on unit cohesion, but provided no evidence and did not respond to contradicting statements entered into the record by former military officials. —Samantha Riedel, Them, 20 Mar. 2025

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