Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “reaction”

See all translations

reaction

noun
 
 
/riˈækʃən/
CAUSED BY SOMETHING [C, U] B2 something you say, feel, or do because of something that has happened: What was his reaction to the news?Reacting and responding
reactions mainly UK the ability to move quickly when something suddenly happens: Drivers need to have quick reactions.Reacting and responding
CHANGE [no plural] a change in the way people behave or think because they do not agree with the way people behaved or thought in the past: In art, there was a reaction against Realism.Reacting and responding
BAD EFFECT [C] B2 an unpleasant feeling or illness caused by something you have eaten or used on your body: A number of people have had a bad reaction to this drug.Reacting and responding
SUBSTANCES [C] a change that happens when two substances are put together: a chemical reaction →  See also chain reaction Physical and chemical processes
(Definition of reaction from the Cambridge Learners Dictionary © Cambridge University Press)
Add Cambridge dictionaries to your browser to your website

Definitions of “reaction” in other dictionaries

Word of the Day

guru

a religious leader or teacher in the Hindu or Sikh religion

Word of the Day

The way we move (Verbs for walking and running)

by Kate Woodford,
March 25, 2015
​​​ This week we’re looking at interesting ways to describe the way that people move. Most of the verbs that we’ll be considering describe how fast or slow people move. Others describe the attitude or state of mind of the person walking or running. Some describe both. Starting with verbs for walking slowly,

Read More 

crossfit noun

March 23, 2015
high-intensity strength training Two women in strappy dresses discussed how much weight they could snatch

Read More