Phrase guide

side effect

noun · 5 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.

  • Australia: Recorded audio is listed in the source snapshot.

1

noun

Meaning 1

An unintended consequence, or secondary result, of any action, in addition to the main or intended consequence of that action.

Definition source: English Wiktionary via Wiktextract

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: by-product

Antonyms: none provided

2

noun

Meaning 2

An unintended consequence, or secondary result, of any action, in addition to the main or intended consequence of that action.

An unintended consequence of a drug or therapy; usually an adverse effect, and not a beneficial one.

Definition source: English Wiktionary via Wiktextract

Topics: medicine, sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: by-product

Antonyms: none provided

3

noun

Meaning 3

An unintended consequence, or secondary result, of any action, in addition to the main or intended consequence of that action.

A change a in state outside of the local environment of the function being called.

Definition source: English Wiktionary via Wiktextract

Topics: computing, engineering, mathematics, natural-sciences, physical-sciences, programming, sciences

Examples

  • The Eiffel programming language is somewhat purist in insisting that functions have no side effects.

Meaning relationships

Synonyms: by-product

Antonyms: none provided

4

noun

Meaning 4

any adverse and unwanted secondary effect

Definition source: Princeton WordNet 3.0

Examples

  • a strategy to contain the fallout from the accounting scandal

Meaning relationships

Synonyms: fallout

Antonyms: none provided

Broader terms: consequence, effect, outcome, result, event, issue, upshot

5

noun

Meaning 5

a secondary and usually adverse effect of a drug or therapy

Definition source: Princeton WordNet 3.0

Examples

  • severe headaches are one of the side effects of the drug

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: effect

Narrower terms: hairy tongue, furry tongue, black tongue

History

Etymology

No etymology was provided for this word.

Across languages

Translations

87 source translations are retained for this English entry.

  • Arabic: أَثَر جَانِبِيّ (ʔaṯar jānibiyy) — unintended consequence of any action
  • Belarusian: пабо́чны эфе́кт (pabóčny efjékt) — unintended consequence of any action
  • Bulgarian: страни́чен ефе́кт (straníčen efékt) — unintended consequence of any action
  • Catalan: efecte secundari — unintended consequence of any action
  • Chinese Mandarin: 副作用 (fùzuòyòng) — unintended consequence of any action
  • Czech: vedlejší účinek — unintended consequence of any action
  • Dutch: nevenwerking — unintended consequence of any action
  • Dutch: neveneffect — unintended consequence of any action
  • Esperanto: kromefiko — unintended consequence of any action
  • Estonian: kõrvalmõju — unintended consequence of any action
  • Finnish: sivuvaikutus — unintended consequence of any action
  • French: effet secondaire — unintended consequence of any action
  • German: Nebenwirkung — unintended consequence of any action
  • German: Nebeneffekt — unintended consequence of any action
  • Greek: παρενέργεια (parenérgeia) — unintended consequence of any action
  • Hebrew: תּוֹפָעַת לְוַאי (tofa'át lvay) — unintended consequence of any action
  • Hindi: दुष्प्रभाव (duṣprabhāv) — unintended consequence of any action
  • Hungarian: mellékhatás — unintended consequence of any action
  • Indonesian: efek samping — unintended consequence of any action
  • Italian: effetto collaterale — unintended consequence of any action
  • Japanese: 副作用 (fukusayō) — unintended consequence of any action
  • Korean: 부작용 (bujagyong) — unintended consequence of any action
  • Macedonian: нуспојава (nuspojava) — unintended consequence of any action
  • Norwegian Bokmål: bieffekt — unintended consequence of any action
  • Polish: efekt uboczny — unintended consequence of any action
  • Polish: skutek uboczny — unintended consequence of any action
  • Portuguese: efeito colateral — unintended consequence of any action
  • Russian: побо́чный эффе́кт (pobóčnyj effékt) — unintended consequence of any action
  • Russian: побо́чное де́йствие (pobóčnoje déjstvije) — unintended consequence of any action
  • Serbo-Croatian: ну̀спојава — unintended consequence of any action
  • Serbo-Croatian: nùspojava — unintended consequence of any action
  • Slovak: vedľajší účinok — unintended consequence of any action
  • Spanish: efecto secundario — unintended consequence of any action
  • Swedish: bieffekt — unintended consequence of any action
  • Turkish: yan etki — unintended consequence of any action
  • Ukrainian: побі́чний ефе́кт (pobíčnyj efékt) — unintended consequence of any action
  • Ukrainian: побі́чна ді́я (pobíčna díja) — unintended consequence of any action
  • Yiddish: בײַעפֿעקט (bayefekt) — unintended consequence of any action
  • Bulgarian: страни́чен ефе́кт (straníčen efékt) — medicine: an adverse effect
  • Catalan: efecte secundari — medicine: an adverse effect
  • Chinese Mandarin: 副作用 (fùzuòyòng) — medicine: an adverse effect
  • Czech: vedlejší účinek — medicine: an adverse effect
  • Dutch: nevenwerking — medicine: an adverse effect
  • Finnish: sivuvaikutus — medicine: an adverse effect
  • French: effet secondaire — medicine: an adverse effect
  • French: effet indésirable — medicine: an adverse effect
  • German: Nebenwirkung — medicine: an adverse effect
  • Greek: παρενέργεια (parenérgeia) — medicine: an adverse effect
  • Hindi: दुष्प्रभाव (duṣprabhāv) — medicine: an adverse effect
  • Hungarian: mellékhatás — medicine: an adverse effect
  • Irish: fo-iamhairt — medicine: an adverse effect
  • Irish: fo-iarsma — medicine: an adverse effect
  • Italian: effetto collaterale — medicine: an adverse effect
  • Japanese: 副作用 (fukusayō) — medicine: an adverse effect
  • Korean: 부작용 (bujagyong) — medicine: an adverse effect
  • Latvian: blakne — medicine: an adverse effect
  • Norwegian Bokmål: bivirkning — medicine: an adverse effect
  • Norwegian Nynorsk: biverknad — medicine: an adverse effect
  • Polish: efekt uboczny — medicine: an adverse effect
  • Portuguese: efeito colateral — medicine: an adverse effect
  • Romanian: efect secundar — medicine: an adverse effect
  • Russian: побо́чный эффе́кт (pobóčnyj effékt) — medicine: an adverse effect
  • Serbo-Croatian: ну̀спојава — medicine: an adverse effect
  • Serbo-Croatian: nùspojava — medicine: an adverse effect
  • Spanish: efecto secundario — medicine: an adverse effect
  • Swedish: biverkan — medicine: an adverse effect
  • Swedish: biverkning — medicine: an adverse effect
  • Thai: ผลข้างเคียง (pǒn-kâang-kiiang) — medicine: an adverse effect
  • Tibetan: ཞོར་རྐྱེན (zhor rkyen) — medicine: an adverse effect
  • Turkish: yan etki — medicine: an adverse effect
  • Ukrainian: побі́чний ефе́кт (pobíčnyj efékt) — medicine: an adverse effect
  • Ukrainian: побі́чна ді́я (pobíčna díja) — medicine: an adverse effect
  • Welsh: sgileffaith — medicine: an adverse effect
  • Bulgarian: страни́чен ефе́кт (straníčen efékt) — computing: a state change caused by a function call
  • Chinese Mandarin: 副作用 (fùzuòyòng) — computing: a state change caused by a function call
  • Czech: vedlejší účinek — computing: a state change caused by a function call
  • Finnish: sivuvaikutus — computing: a state change caused by a function call
  • French: effet de bord — computing: a state change caused by a function call
  • German: Nebeneffekt — computing: a state change caused by a function call
  • German: Seiteneffekt — computing: a state change caused by a function call
  • Hungarian: mellékhatás — computing: a state change caused by a function call
  • Hungarian: kísérő jelenség — computing: a state change caused by a function call
  • Irish: fo-iarsma — computing: a state change caused by a function call
  • Japanese: 副作用 (fukusayō) — computing: a state change caused by a function call
  • Korean: 부작용 (bujagyong) — computing: a state change caused by a function call
  • Polish: efekt uboczny — computing: a state change caused by a function call
  • Russian: побо́чный эффе́кт (pobóčnyj effékt) — computing: a state change caused by a function call