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reaction - definition and synonyms


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noun reaction pronunciation in British English /riˈækʃ(ə)n/
Word Forms
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  1. 1
    [countable] the way that you feel or behave as a result of something that happens
    My mother’s initial reaction was quite unexpected.
    1. a.
      [usually singular] a sudden feeling of being tired, upset etc, for example after an unpleasant or exciting experience
      The reaction of any individual trauma victim is difficult to predict.
      reaction to: Shock is a natural reaction to such bad news.
    See also knee-jerk
  2. 2
    [countable] a bad effect on your body caused by food, medicine, or another substance
    reaction to: Some people’s skin has an allergic reaction to certain types of fabric.
    have/suffer a reaction: He suffered a violent reaction to the medicine.
  3. 3


    [plural] your ability to think and act quickly in a difficult or dangerous situation
    A tragedy was only prevented by the driver’s quick reactions.
  4. 4
    [countable] chemistry a process in which a chemical change happens
    Temperature can affect the rate of a chemical reaction.
    reaction between: We are studying reactions between a number of metals and acids.
    1. a.
      [countable/uncountable] physics a physical force that is caused by an opposite physical force, usually producing a form of energy
      a nuclear reaction
      Newton teaches that action and reaction are equal and opposite.
    See also chain reaction
  5. 5
    [singular] an attitude of wanting to do things in a different way from the way that they were done in the past
    reaction against: The reaction against traditional styles continued for another 50 years.


a meal served in the evening which consists of foods traditionally eaten at breakfast

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