re ‧ act S3 W3 AC /riˈækt/ BrE AmE verb [intransitive]
[ Word Family: noun : ↑ reaction , ↑ reactor , ↑ reactionary , ↑ overreaction ; verb : ↑ react , ↑ overreact ; adjective : ↑ reactionary , ↑ reactive ]
1 . BEHAVIOUR/FEELINGS to behave in a particular way or show a particular emotion because of something that has happened or been said ⇨ respond
react to
How did Wilson react to your idea?
He reacted angrily to the suggestion that he had lied.
She reacted very badly (=was very upset) when her parents split up.
You have to react quickly to circumstances.
react by doing something
The government reacted by declaring all strikes illegal.
⇨ ↑ overreact
2 . CHEMICALS technical if a chemical substance reacts, it changes when it is mixed with another chemical substance
react with
The calcium reacts with sulphur in the atmosphere.
3 . PRICES if prices or financial markets react to something that happens, they increase or decrease in value because of it
react to
Oil prices reacted sharply (=reacted a lot) to news of the crisis in the Middle East.
The market reacted favourably to the announcement.
4 . BECOME ILL to become ill when a chemical or drug goes into your body, or when you eat a particular kind of food ⇨ respond
react to
Quite a lot of children react badly to antibiotics.
• • •
COLLOCATIONS
■ adverbs
▪ react badly (=become annoyed, upset etc)
Do you react badly to criticism?
▪ react angrily/violently
The Prime Minister reacted angrily to these accusations.
▪ react strongly
Scott reacted strongly when he felt he was being treated unjustly.
▪ react quickly/swiftly
The goalkeeper had to react quickly.
▪ react differently
People react differently to stress.
▪ react positively/negatively (=with positive/negative emotions or opinions)
We want versatile people who react positively to change.
▪ react cautiously (=carefully, so that you avoid danger or risk)
The United States has reacted cautiously to the offer.
▪ react instinctively (=without thinking or needing to think)
She reacted instinctively and reached for her gun.
react against something phrasal verb
to show that you dislike someone else’s ideas or ways of doing something, by deliberately doing the opposite:
He reacted strongly against his religious upbringing.