harmful

H4A1R1M3F4U1L1
UK/ˈhɑːmfl̩/US/ˈhɑɹmfl̩/

adjective

Causing or likely to cause harm or damage; injurious.

“Smoking is harmful to the lungs.”

Similar
injuriousdamagingdeleteriousdetrimentalhurtfulinimicalmischievousnocent
Opposite
beneficialharmlesshelpfulvaluableinnocent
OriginMiddle English harmful ← Old English *hearmful →
CommonScrabble 15
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Meanings

adjectiveharmful (comparative harmfuller or more harmful, superlative harmfullest or most harmful)

comparative harmfuller · comparative more harmful · superlative harmfullest · superlative most harmful · alternative harmfull

  1. Causing or likely to cause harm or damage; injurious.

    Smoking is harmful to the lungs.

    2 more examples

    Wear a hat to protect your skin from harmful sunlight.

    Burning fossil fuels is harmful to the environment.

    Synonyms: injurious, damaging, deleterious, detrimental, hurtful, inimical, mischievous, nocent

Synonyms & antonyms

adjectiveCausing or likely to cause harm or damage; injurious.

Similar
injuriousdamagingdeleteriousdetrimentalhurtfulinimicalmischievousnocentnocuousnoxiousnoisomeprejudicialscathandscathelsullenvenom
Opposite
beneficialharmlesshelpfulvaluableinnocentinnocuousinnoxiousinoffensiveundamagingunharmful

More synonyms by meaning

adjectivecausing or capable of causing harm

Similar
abusivebadbruisingdeleterioushurtfulinjurious
Opposite
harmless
Also see
abusivebadbruisingcalamitouscalumniatorycalumniouscatastrophiccounterproductivedamagingdefamatorydeleteriousdenigrativedenigratorydestructivedetrimentaldisastrousevilhurtfulhurtsomeillinjuriousinsidiouslibelousmischievousnocentnoisomenoxiouspeevishperniciousprejudicialprejudiciousruinousscathefulslanderousstabbingsubtlewoefulwounding

Synonym sets from Open English WordNet, CC BY 4.0.

Origin

  1. Old English*hearmful
  2. Middle Englishharmful
  3. Englishharmful

From Middle English harmful, from Old English *hearmful (suggested by hearmfullīċ (“harmful; hurtful”)), equivalent to harm + -ful. Cognate with German harmvoll, Danish harmfuld, Swedish harmfull.

More words from Middle English, Old English

Full word history & related roots →

Translations

Ancient Greek βλαπτικός, δηλητήριος
  • βλαπτικός (blaptikós)likely to be damaging
  • δηλητήριος (dēlētḗrios)likely to be damaging
Arabic ضَارّ, مُضِرّ
  • ضَارّ (ḍārr)likely to be damaging
  • مُضِرّ (muḍirr)likely to be damaging
Bengali ক্ষতিকর, ক্ষতিকারক
  • ক্ষতিকর (khotikor)likely to be damaging
  • ক্ষতিকারক (khotikarok)likely to be damaging
Bulgarian вреден, пакостен
  • вреден (vreden)likely to be damaging
  • пакостен (pakosten)likely to be damaging
Catalan nociu
  • nociulikely to be damaging
Chinese Mandarin 有害, 不良
  • 有害 (yǒuhài)likely to be damaging
  • 不良 (bùliáng)likely to be damaging
Czech škodlivý
  • škodlivýlikely to be damaging
Danish skadelig
  • skadeliglikely to be damaging
Dutch schadelijk
  • schadelijklikely to be damaging
Finnish vahingollinen, haitallinen
  • vahingollinenlikely to be damaging
  • haitallinenlikely to be damaging
French dangereux, nuisible
  • dangereuxlikely to be damaging
  • nuisiblelikely to be damaging
  • nociflikely to be damaging
  • préjudiciablelikely to be damaging
German schädlich
  • schädlichlikely to be damaging
Hindi हानिकारक, अहितकर
  • हानिकारक (hānikārak)likely to be damaging
  • अहितकर (ahitkar)likely to be damaging
  • अपकारी (apkārī)likely to be damaging
  • घातक (ghātak)likely to be damaging
Hungarian káros, kártékony
  • károslikely to be damaging
  • kártékonylikely to be damaging
Icelandic skaðlegur
  • skaðlegurlikely to be damaging
Indonesian berbahaya
  • berbahayalikely to be damaging
Irish aimhleasach, biniúil
  • aimhleasachlikely to be damaging
  • biniúillikely to be damaging
  • damáisteachlikely to be damaging
  • díobhálachlikely to be damaging
  • dochrachlikely to be damaging
  • éigineáillikely to be damaging
  • mímhaitheasachlikely to be damaging
  • olclikely to be damaging
  • olcachlikely to be damaging
  • urchóideachlikely to be damaging
Italian dannoso, nocivo
  • dannosolikely to be damaging
  • nocivolikely to be damaging
Japanese 有害な
  • 有害な (yūgai-na)likely to be damaging
Korean 해로운, 유해한
  • 해로운 (haeroun)likely to be damaging
  • 유해한 (yuhaehan)likely to be damaging
Latin nocuus, noxius
  • nocuuslikely to be damaging
  • noxiuslikely to be damaging
Malay berbahaya
  • berbahayalikely to be damaging
Māori whakakino, whakawhara
  • whakakinolikely to be damaging
  • whakawharalikely to be damaging
Norwegian skadelig
  • skadeliglikely to be damaging
Persian مضر
  • مضرlikely to be damaging
Polish szkodliwy
  • szkodliwylikely to be damaging
Portuguese prejudicial, nocivo
  • prejudiciallikely to be damaging
  • nocivolikely to be damaging
  • danosolikely to be damaging
  • daninholikely to be damaging
Romanian nociv, prejudiciabil
  • nocivlikely to be damaging
  • prejudiciabillikely to be damaging
  • dăunătorlikely to be damaging
  • vătămătorlikely to be damaging
  • păgubitorlikely to be damaging
  • stricătorlikely to be damaging
Russian вре́дный, вредоно́сный
  • вре́дный (vrédnyj)likely to be damaging
  • вредоно́сный (vredonósnyj)likely to be damaging
  • зловре́дный (zlovrédnyj)likely to be damaging
Slovak škodlivý
  • škodlivýlikely to be damaging
Spanish perjudicial, perjudicador
  • perjudiciallikely to be damaging
  • perjudicadorlikely to be damaging
  • lesivolikely to be damaging
Swedish skadlig
  • skadliglikely to be damaging
Tagalog mapaminsala, nakapipinsala
  • mapaminsalalikely to be damaging
  • nakapipinsalalikely to be damaging
  • nakasisiralikely to be damaging
  • nakasasamalikely to be damaging
Turkish zararlı
  • zararlılikely to be damaging
Ukrainian шкідли́вий, вадли́вий
  • шкідли́вий (škidlývyj)likely to be damaging
  • вадли́вий (vadlývyj)likely to be damaging
Urdu مضر
  • مضرlikely to be damaging
Cite this entry
APA

harmful. (n.d.). In WatkinsX Dictionary. Retrieved November 2, 2026, from https://dictionary.watkinsx.com/word/harmful

MLA

“harmful.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/harmful. Accessed November 2, 2026.

Chicago

WatkinsX Dictionary, s.v. “harmful,” accessed November 2, 2026, https://dictionary.watkinsx.com/word/harmful.

Source: harmful on Wiktionary, CC BY-SA 4.0.