Standard Lemma guide

react

noun · verb · 10 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.

  • /ɹiːˈækt/
  • Southern-England: Recorded audio is listed in the source snapshot.
  • rhymes with -ækt
  • CMU ARPABET: R IY0 AE1 K T Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.

1

noun

Meaning 1

An emoji used to express a reaction to a post on social media.

Definition source: English Wiktionary via Wiktextract

Usage: Internet

Examples

  • Sad reacts only

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

verb

Meaning 2

To act in response.

Definition source: English Wiktionary via Wiktextract

Usage: intransitive

Examples

  • How did she react to the news?

Meaning relationships

Synonyms: take

Antonyms: none provided

3

verb

Meaning 3

To act or perform a second time; to do over again; to reenact.

Definition source: English Wiktionary via Wiktextract

Usage: archaic, transitive

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

4

verb

Meaning 4

To return an impulse or impression; to resist the action of another body by an opposite force

Definition source: English Wiktionary via Wiktextract

Usage: intransitive

Topics: natural-sciences, physical-sciences, physics

Examples

  • Every body reacts on the body that impels it from its natural state.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

5

verb

Meaning 5

To act upon each other; to exercise a reciprocal or a reverse effect, as two or more chemical agents; to act in opposition.

Definition source: English Wiktionary via Wiktextract

Usage: intransitive

Topics: chemistry, natural-sciences, physical-sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

6

verb

Meaning 6

To cause chemical agents to react; to cause one chemical agent to react with another.

Definition source: English Wiktionary via Wiktextract

Usage: transitive

Topics: chemistry, natural-sciences, physical-sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

7

verb

Meaning 7

To post a reaction (icon or emoji indicating how one feels about a posted message).

Definition source: English Wiktionary via Wiktextract

Usage: Internet, intransitive

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

8

verb

Meaning 8

undergo a chemical reaction; react with another substance under certain conditions

Definition source: Princeton WordNet 3.0

Examples

  • The hydrogen and the oxygen react

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: change state, turn

Narrower terms: bromate, brominate

9

verb

Meaning 9

show a response or a reaction to something

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: respond

Antonyms: none provided

Broader terms: act, move

Narrower terms: treat, bristle, flip, flip out, overreact, answer, accept, stool, respond, greet, explode, refuse, decline, consent, go for, wonder, marvel, notice, acknowledge, resist, reject

10

verb

Meaning 10

act against or in opposition to

Definition source: Princeton WordNet 3.0

Examples

  • She reacts negatively to everything I say

Meaning relationships

Synonyms: oppose

Antonyms: none provided

Broader terms: act, move

Narrower terms: pursue, follow up on, act on, buck, go against

History

Etymology

From re- + act. Piecewise doublet of redact.

Across languages

Translations

46 source translations are retained for this English entry.

  • Esperanto: reagi — to act in response
  • Finnish: reagoida — to act in response
  • French: réagir — to act in response
  • Galician: reaccionar — to act in response
  • Georgian: რეაგირება (reagireba) — to act in response
  • Georgian: რეაგირებს (reagirebs) — to act in response
  • Italian: reagire — to act in response
  • Korean: 반응하다 (baneunghada) — to act in response
  • Polish: zareagować — to act in response
  • Polish: reagować — to act in response
  • Portuguese: reagir — to act in response
  • Romanian: reacționa — to act in response
  • Russian: реаги́ровать (reagírovatʹ) — to act in response
  • Russian: отреаги́ровать (otreagírovatʹ) — to act in response
  • Russian: среаги́ровать (sreagírovatʹ) — to act in response
  • Spanish: reaccionar — to act in response
  • Bulgarian: изпълнявам отново (izpǎlnjavam otnovo) — to act or perform a second time
  • Finnish: tehdä uudelleen — to act or perform a second time
  • French: agir de nouveau — to act or perform a second time
  • French: encore agir — to act or perform a second time
  • Bulgarian: реагирам (reagiram) — to return an impulse or impression
  • Catalan: reaccionar — to return an impulse or impression
  • Dutch: reageren — to return an impulse or impression
  • Finnish: reagoida — to return an impulse or impression
  • Finnish: vaikuttaa vastaan — to return an impulse or impression
  • French: réagir — to return an impulse or impression
  • German: reagieren — to return an impulse or impression
  • Greek: αντιδρώ (antidró) — to return an impulse or impression
  • Occitan: reagir — to return an impulse or impression
  • Polish: reagować — to return an impulse or impression
  • Polish: zareagować — to return an impulse or impression
  • Portuguese: reagir — to return an impulse or impression
  • Spanish: reaccionar — to return an impulse or impression
  • Swedish: reagera — to return an impulse or impression
  • Turkish: reaksiyon göstermek — to return an impulse or impression
  • Ukrainian: реагува́ти (reahuváty) — to return an impulse or impression
  • Ukrainian: відреагува́ти (vidreahuváty) — to return an impulse or impression
  • Ukrainian: зреагува́ти (zreahuváty) — to return an impulse or impression
  • Finnish: reagoida — to act upon each other (in chemistry)
  • French: réagir — to act upon each other (in chemistry)
  • Irish: imoibrigh — to act upon each other (in chemistry)
  • Polish: reagować — to act upon each other (in chemistry)
  • Polish: zareagować — to act upon each other (in chemistry)
  • Russian: реаги́ровать (reagírovatʹ) — to act upon each other (in chemistry)
  • Russian: прореаги́ровать (proreagírovatʹ) — to act upon each other (in chemistry)
  • Russian: среаги́ровать (sreagírovatʹ) — to act upon each other (in chemistry)