Standard Lemma guide

reaction

noun · 12 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.

  • US: Recorded audio is listed in the source snapshot.
  • /ɹiˈækʃən/
  • rhymes with -ækʃən
  • CMU ARPABET: R IY0 AE1 K SH AH0 N Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.

1

noun

Meaning 1

An action or statement in response to a stimulus or other event.

Definition source: English Wiktionary via Wiktextract

Examples

  • The announcement of the verdict brought a violent reaction.
  • You were in the courtroom. What is your reaction?
  • When I last tried to eat strawberries I had a terrible allergic reaction.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

A transformation in which one or more substances is converted into another by combination or decomposition.

Definition source: English Wiktionary via Wiktextract

Topics: chemistry, natural-sciences, physical-sciences

Examples

  • In this reaction, the acid and base will neutralize each other, producing a salt.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

3

noun

Meaning 3

Reactionary politics; a period in which reactionary thought or politics is resurgent or dominant.

Definition source: English Wiktionary via Wiktextract

Topics: government, politics

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

4

noun

Meaning 4

Unpurposeful behavior.

Definition source: English Wiktionary via Wiktextract

Usage: Austrian

Topics: economics, sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

5

noun

Meaning 5

An icon or emoji appended to a posted message by a user to express their feeling about it.

Definition source: English Wiktionary via Wiktextract

Usage: Internet

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

6

noun

Meaning 6

doing something in opposition to another way of doing it that you don't like

Definition source: Princeton WordNet 3.0

Examples

  • his style of painting was a reaction against cubism

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: resistance, opposition

Narrower terms: backlash

7

noun

Meaning 7

a bodily process occurring due to the effect of some antecedent stimulus or agent

Definition source: Princeton WordNet 3.0

Examples

  • a bad reaction to the medicine
  • his responses have slowed with age

Meaning relationships

Synonyms: response

Antonyms: none provided

Broader terms: bodily process, body process, bodily function, activity

Narrower terms: automatism, rebound, overreaction, galvanic skin response, GSR, psychogalvanic response, electrodermal response, electrical skin response, Fere phenomenon, Tarchanoff phenomenon, immune response, immune reaction, immunologic response, tropism, taxis, kinesis, double take, reflex, reflex response, reflex action, instinctive reflex, innate reflex, inborn reflex, unconditioned reflex, physiological reaction, learned reaction, learned response, passage, passing, answer, transfusion reaction

8

noun

Meaning 8

an idea evoked by some experience

Definition source: Princeton WordNet 3.0

Examples

  • his reaction to the news was to start planning what to do

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: idea, thought

9

noun

Meaning 9

extreme conservatism in political or social matters

Definition source: Princeton WordNet 3.0

Examples

  • the forces of reaction carried the election

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: conservatism, conservativism

10

noun

Meaning 10

a response that reveals a person's feelings or attitude

Definition source: Princeton WordNet 3.0

Examples

  • he was pleased by the audience's reaction to his performance
  • John feared his mother's reaction when she saw the broken lamp

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: response

11

noun

Meaning 11

(mechanics) the equal and opposite force that is produced when any force is applied to a body

Definition source: Princeton WordNet 3.0

Examples

  • every action has an equal and opposite reaction

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: force

12

noun

Meaning 12

(chemistry) a process in which one or more substances are changed into others

Definition source: Princeton WordNet 3.0

Examples

  • there was a chemical reaction of the lime with the ground water

Meaning relationships

Synonyms: chemical reaction

Antonyms: none provided

Broader terms: chemical process, chemical change, chemical action

Narrower terms: addition reaction, aldol reaction, chain reaction, chemical equilibrium, equilibrium, decomposition, decomposition reaction, chemical decomposition reaction, displacement, displacement reaction, double decomposition, double decomposition reaction, metathesis, elimination reaction, endothermic reaction, exothermic reaction, hydrolysis, neutralization, neutralisation, neutralization reaction, neutralisation reaction, oxidation, oxidization, oxidisation, oxidation-reduction, oxidoreduction, redox, photochemical reaction, reduction, reducing, saponification

History

Etymology

Inherited from Middle English reaccion, from Old French reaction, from Latin reāctiō, from the verb reagō, from re- (“again”) + agō (“to act”); more at re-, action; equivalent to react + -ion.

Across languages

Translations

138 source translations are retained for this English entry.

  • Afrikaans: reaksie — action in response to an event
  • Albanian: reagim — action in response to an event
  • Arabic: رَدّ فِعْل (radd fiʕl) — action in response to an event
  • Arabic: تَفَاعُل (tafāʕul) — action in response to an event
  • Armenian: ռեակցիա (ṙeakcʻia) — action in response to an event
  • Azerbaijani: reaksiya — action in response to an event
  • Azerbaijani: əksüləməl — action in response to an event
  • Azerbaijani: təpki — action in response to an event
  • Belarusian: рэа́кцыя (reákcyja) — action in response to an event
  • Bengali: প্রতিক্রিয়া (protikriẏa) — action in response to an event
  • Bulgarian: реа́кция (reákcija) — action in response to an event
  • Catalan: reacció — action in response to an event
  • Chinese Mandarin: 反應 /反应 (fǎnyìng) — action in response to an event
  • Chinese Mandarin: 反動 /反动 (fǎndòng) — action in response to an event
  • Czech: reakce — action in response to an event
  • Danish: reaktion — action in response to an event
  • Dutch: reactie — action in response to an event
  • Esperanto: reakcio — action in response to an event
  • Esperanto: reago — action in response to an event
  • Estonian: reaktsioon — action in response to an event
  • Finnish: reaktio — action in response to an event
  • Finnish: vaikutus — action in response to an event
  • Finnish: vastavaikutus — action in response to an event
  • Finnish: vaste — action in response to an event
  • French: réaction — action in response to an event
  • Galician: reacción — action in response to an event
  • Georgian: რეაქცია (reakcia) — action in response to an event
  • German: Reaktion — action in response to an event
  • Greek: αντίδραση (antídrasi) — action in response to an event
  • Hebrew: תְּגוּבָה (t'guvá) — action in response to an event
  • Hindi: प्रतिक्रिया (pratikriyā) — action in response to an event
  • Hindi: प्रक्रिया (prakriyā) — action in response to an event
  • Hungarian: reakció — action in response to an event
  • Indonesian: reaksi — action in response to an event
  • Irish: frithghníomhaíocht — action in response to an event
  • Italian: reazione — action in response to an event
  • Japanese: 反応 (hannō) — action in response to an event
  • Japanese: 反動 (handō) — action in response to an event
  • Japanese: リアクション (riakushon) — action in response to an event
  • Kazakh: реакция (reaksiä) — action in response to an event
  • Khmer: ប្រតិកម្ម (praʼtekam) — action in response to an event
  • Korean: 반응 (baneung) — action in response to an event
  • Korean: 반동 (bandong) — action in response to an event
  • Korean: 리액션 (riaeksyeon) — action in response to an event
  • Kyrgyz: реакция (reaktsiya) — action in response to an event
  • Lao: ປະຕິກິລິຍາ (pa ti ki li nyā) — action in response to an event
  • Lao: ປະຕິກິຣິຍາ (pa ti ki ri nyā) — action in response to an event
  • Latin: reāctiō — action in response to an event
  • Latvian: reakcija — action in response to an event
  • Lithuanian: reakcija — action in response to an event
  • Luxembourgish: Reaktioun — action in response to an event
  • Macedonian: реакција (reakcija) — action in response to an event
  • Malay: reaksi — action in response to an event
  • Malay: tindak balas — action in response to an event
  • Maltese: reazzjoni — action in response to an event
  • Marathi: प्रतिक्रिया (pratikriyā) — action in response to an event
  • Mongolian: урвал (urval) — action in response to an event
  • Norwegian Bokmål: reaksjon — action in response to an event
  • Norwegian Nynorsk: reaksjon — action in response to an event
  • Pannonian Rusyn: реакция (reakcija) — action in response to an event
  • Persian: واکنش (vâkoneš) — action in response to an event
  • Persian: رآکسیون (re-âksyon) — action in response to an event
  • Polish: reakcja — action in response to an event
  • Portuguese: reação — action in response to an event
  • Romanian: reacție — action in response to an event
  • Russian: реа́кция (reákcija) — action in response to an event
  • Sanskrit: प्रतिक्रिया (pratikriyā) — action in response to an event
  • Sanskrit: प्रक्रिया (prakriyā) — action in response to an event
  • Serbo-Croatian: реа̀кција — action in response to an event
  • Serbo-Croatian: reàkcija — action in response to an event
  • Slovak: reakcia — action in response to an event
  • Slovene: reakcija — action in response to an event
  • Spanish: reacción — action in response to an event
  • Swahili: mmenyuko — action in response to an event
  • Swedish: reaktion — action in response to an event
  • Tagalog: reaksyon — action in response to an event
  • Tajik: таассур (taassur) — action in response to an event
  • Tajik: реаксия (reaksiya) — action in response to an event
  • Tajik: вокуниш (vokuniš) — action in response to an event
  • Telugu: ప్రతిచర్య (praticarya) — action in response to an event
  • Telugu: ప్రతిక్రియ (pratikriya) — action in response to an event
  • Thai: ปฏิกิริยา (bpà-dtì-gì-rí-yaa) — action in response to an event
  • Turkish: tepki — action in response to an event
  • Turkish: reaksiyon — action in response to an event
  • Turkmen: reaksiýa — action in response to an event
  • Ukrainian: реа́кція (reákcija) — action in response to an event
  • Uzbek: reaksiya — action in response to an event
  • Uzbek: sezish — action in response to an event
  • Vietnamese: phản ứng — action in response to an event
  • Welsh: adwaith — action in response to an event
  • Welsh: ymateb — action in response to an event
  • Afrikaans: reaksie — chemical transformation
  • Arabic: تَفَاعُل (tafāʕul) — chemical transformation
  • Armenian: փոխազդեցություն (pʻoxazdecʻutʻyun) — chemical transformation
  • Armenian: ռեակցիա (ṙeakcʻia) — chemical transformation
  • Belarusian: рэа́кцыя (reákcyja) — chemical transformation
  • Bulgarian: реа́кция (reákcija) — chemical transformation
  • Catalan: reacció — chemical transformation
  • Chinese Mandarin: 反應 /反应 (fǎnyìng) — chemical transformation
  • Czech: reakce — chemical transformation
  • Danish: reaktion — chemical transformation
  • Finnish: reaktio — chemical transformation
  • French: réaction — chemical transformation
  • Georgian: რეაქცია (reakcia) — chemical transformation
  • German: Reaktion — chemical transformation
  • Greek: αντίδραση (antídrasi) — chemical transformation
  • Icelandic: hvörf — chemical transformation
  • Icelandic: hvarf — chemical transformation
  • Irish: imoibriú — chemical transformation
  • Italian: reazione — chemical transformation
  • Japanese: 反応 (hannō) — chemical transformation
  • Kazakh: реакция (reaksiä) — chemical transformation
  • Korean: 반응 (baneung) — chemical transformation
  • Luxembourgish: Reaktioun — chemical transformation
  • Malay: tindak balas — chemical transformation
  • Malay: reaksi — chemical transformation
  • Māori: tauhohenga — chemical transformation
  • Marathi: अभिक्रिया (abhikriyā) — chemical transformation
  • Norwegian Bokmål: reaksjon — chemical transformation
  • Norwegian Nynorsk: reaksjon — chemical transformation
  • Portuguese: reação — chemical transformation
  • Romanian: reacție — chemical transformation
  • Russian: реа́кция (reákcija) — chemical transformation
  • Spanish: reacción — chemical transformation
  • Tagalog: balibilos — chemical transformation
  • Telugu: చర్య (carya) — chemical transformation
  • Thai: ปฏิกิริยา (bpà-dtì-gì-rí-yaa) — chemical transformation
  • Turkish: tepkime — chemical transformation
  • Ukrainian: реа́кція (reákcija) — chemical transformation
  • Vietnamese: phản ứng — chemical transformation
  • Welsh: adwaith — chemical transformation
  • Welsh: ymateb — chemical transformation
  • Azerbaijani: irtica — reactionary politics
  • Azerbaijani: reaksiya — reactionary politics
  • Bulgarian: реакционерство (reakcionerstvo) — reactionary politics
  • Finnish: taantumus — reactionary politics
  • German: Reaktion — reactionary politics
  • Hungarian: reakció — reactionary politics
Real reading context

reaction in complete knowledge articles