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
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