Synonyms of noxious

noxious

adjective

ˈnäk-shəs 

1

as in poisonous

bad for the well-being of the body

mixing bleach and ammonia can cause noxious fumes that can seriously harm you

Synonyms & Similar Words

• poisonous
• toxic
• unhealthful
• unwholesome
• noisome
• unhealthy
• sickly
• insalubrious
• insanitary
• unsanitary
• unhygienic
• lethal
• fatal
• germy
• nonnutritious
• mortal

Antonyms & Near Antonyms

• healthy
• healthful
• sanitary
• hygienic
• nutritious

2

as in harmful

causing or capable of causing harm

noxious smog that for years has been encrusting the historic cathedral with soot

Synonyms & Similar Words

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

Antonyms & Near Antonyms

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

3

as in disgusting

causing intense displeasure, disgust, or resentment

the website reserved the right to remove and report hate speech and other noxious types of postings

Synonyms & Similar Words

• disgusting
• ugly
• awful
• horrible
• sickening
• obnoxious
• hideous
• obscene
• shocking
• offensive
• dreadful
• nasty
• unpleasant
• evil
• loathsome
• odious
• repulsive
• repugnant
• abominable
• revolting
• noisome
• gross
• horrid
• appalling
• repellent
• distasteful
• abhorrent
• nauseating
• rancid
• gruesome
• scandalous
• undesirable
• terrible
• foul
• horrific
• horrendous
• nauseous
• vile
• fulsome
• disturbing
• unwanted
• objectionable
• hateful
• disagreeable
• monstrous
• unwholesome
• detestable
• miserable
• horrifying
• contemptible
• brackish
• unhealthy
• despicable
• heinous
• grim
• unsavory
• unwelcome
• ghastly
• unspeakable
• sick
• nightmarish
• execrable
• lurid
• frightful
• exceptionable
• grisly
• sickly
• barbarous
• atrocious
• unholy
• macabre
• uncivilized
• dislikable
• ungodly
• lousy
• hard
• upsetting
• unchristian
• sickish
• distressing
• off-putting

Antonyms & Near Antonyms

• innocuous
• desirable
• acceptable
• pleasant
• inoffensive
• attractive
• delightful
• sweet
• delicious
• agreeable
• congenial
• alluring
• pleasurable
• heavenly
• enjoyable
• welcome
• nice
• appealing
• satisfying
• delectable
• palatable
• gratifying
• luscious
• dreamy
• pleasing
• felicitous
• savory
• likable
• dulcet
• inviting
• darling
• blessed
• unobjectionable
• unexceptionable
• healthful
• wholesome
• healthy
• salubrious
• salutary
• restorative
• delightsome

Synonym Chooser

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

Some common synonyms of noxious are baneful, deleterious, detrimental, and pernicious. While all these words mean "exceedingly harmful," noxious applies to what is both offensive and injurious to the health of a body or mind.

noxious chemical fumes

When is it sensible to use baneful instead of noxious?

The words baneful and noxious can be used in similar contexts, but baneful implies injury through poisoning or destroying.

the baneful notion that discipline destroys creativity

When would deleterious be a good substitute for noxious?

In some situations, the words deleterious and noxious are roughly equivalent. However, deleterious applies to what has an often unsuspected harmful effect.

a diet found to have deleterious effects

When could detrimental be used to replace noxious?

While the synonyms detrimental and noxious are close in meaning, detrimental implies obvious harmfulness to something specified.

the detrimental effects of excessive drinking

When might pernicious be a better fit than noxious?

The meanings of pernicious and noxious largely overlap; however, 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 noxious

The company is challenging the county’s decision to award a contract to Oransi LLC for up to 30,000 portable air purifiers intended for residents affected by noxious gases emanating from the Tijuana River. —Walker Armstrong, San Diego Union-Tribune, 8 June 2026

Israeli military strikes on Iranian oil infrastructure have sparked days-long conflagrations, releasing a plume of noxious sulflur dioxide over an area roughly the size of Italy. —Tony Briscoe, Los Angeles Times, 4 June 2026

Yet the Declaration of Independence also proclaimed ideals that contradicted those noxious deeds. —Michael Kazin, The Atlantic, 3 June 2026

Sewers can contain numerous hazards, including noxious and potentially deadly gases, unstable surfaces, flooding risks, and confined spaces. —Brie Stimson, FOXNews.com, 31 May 2026