noxious

English

Alternative forms

• noctious (obsolete)

Etymology

From Latin noxius (“hurtful, injurious”), from noxa (“hurt, injury”), from nocere (“to hurt, injure”); see nocent.

Pronunciation

• (Received Pronunciation) IPA^(key): /ˈnɒkʃəs/
• (General American) IPA^(key): /ˈnɑkʃəs/

• Audio (Southern England):

  (file)

Adjective

noxious (comparative more noxious, superlative most noxious)

1. Harmful; injurious.
   • 1822, John Barclay, chapter I, in An Inquiry Into the Opinions, Ancient and Modern, Concerning Life and Organization‎^[1], Edinburgh; London: Bell & Bradfute; Waugh & Innes; G. & W. B. Whittaker, section I, page 1:

     In the living state, the body is observed to […] reject what is noxious; [...]

   • 2014 June 14, “It's a gas”, in The Economist‎^[2], volume 411, number 8891, archived from the original on 9 January 2025:

     [...] many old sewers have been neglected and are in dire need of repair. If that repair does not come in time, the result is noxious and potentially hazardous.

   • 2025 July 9, Mike Isaac, Kate Conger, “X CEO Linda Yaccarino Says She Is Leaving Elon Musk’s Platform”, in The New York Times‎^[3], →ISSN, archived from the original on 9 July 2025:

     Immediately upon joining, Ms. Yaccarino had her work cut out for her. Mr. Musk quickly made changes that tore up much of the good will Twitter had with users, employees and advertisers, including changing speech policies that allowed noxious content to circulate on the platform. Many advertisers left.

Synonyms

• harmful
• injurious
• scathing
• see also Thesaurus:harmful

Derived terms

• nonnoxious
• noxiously
• noxiousness
• noxious stimulus
• noxious trade
• unnoxious

Related terms

Etymologically related to noxia (“hurt, injury, damage”)

• obnoxious
• nocent
• innocent

Collocations

with nouns

• noxious substance
• noxious chemical
• noxious fumes
• noxious gas
• noxious odor
• noxious plant
• noxious weed
• noxious animal
• noxious stimulus
• noxious stimulation

Translations

harmful — see also mephitic,‎ damaging

• Arabic: please add this translation if you can
• Asturian: nocivu (ast) m, dañible (ast) m or f
• Basque: kaltegarri (eu)
• Bulgarian: вреден (bg) (vreden), нездравословен (bg) (nezdravosloven)
• Catalan: nociu (ca)
• Chinese:

  Mandarin: please add this translation if you can

• Corsican: nucivu m
• Esperanto: venefna
• Estonian: kahjur-
• Finnish: vahingollinen (fi), haitallinen (fi), myrkyllinen (fi)
• French: nocif (fr) m
• Friulian: nocîf
• Galician: nocivo (gl) m, daniño (gl) m
• German: Schad- (de), schädlich (de)
• Hindi: please add this translation if you can
• Hungarian: kártékony (hu), ártalmas (hu)
• Italian: insalubre (it), nocivo (it), malsano (it)
• Japanese: 有毒な (ゆうどくな, yūdokuna)
• Korean: 유해한 (yuhaehan)
• Latin: noxius m
• Latvian: kaitīgs
• Māori: orotā
• Persian: please add this translation if you can
• Polish: szkodliwy (pl), niezdrowy (pl)
• Portuguese: nocivo (pt) m, daninho (pt) m
• Romanian: nociv (ro) m or n, vătămător (ro) m or n, nesănătos (ro) m or n
• Russian: ядови́тый (ru) (jadovítyj), вре́дный (ru) (vrédnyj)
• Serbo-Croatian:

  Cyrillic: ште̏тан m

  Latin: štȅtan (sh) m

• Spanish: nocivo (es), nocible, nocente
• Turkish: zararlı (tr)
• Vietnamese: độc hại (vi)

Further reading

• “noxious”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.
• William Dwight Whitney, Benjamin E[li] Smith, editors (1911), “noxious”, in The Century Dictionary […], New York, N.Y.: The Century Co., →OCLC.
• “noxious”, in OneLook Dictionary Search.
• Douglas Harper (2001–2026), “noxious”, in Online Etymology Dictionary.