verb
react
ree-AKT
verb
1
To act, respond, or behave in a particular way because of something that has happened.
"She reacted angrily to the news."
"How did he react when you told him?"
2
Of chemical substances, to undergo a transformation when combined with another substance.
"Sodium reacts violently with water."
3
To add a small icon or emoji to a social media post to express a feeling about it.
"Dozens of people reacted to her post with a laughing emoji."
How to Use React
Learner’s notesIn plain EnglishTo respond to something — with a feeling, an action, or (for chemicals) a transformation.
Common pairings
react to news
react quickly
chemicals react
Word Forms
reacted past tense, reacts plural, reacts singular
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Etymology
Built from re- ("again") and act, echoing the Latin reagere ("to act back").