1. A bodily process occurring due to the effect of some antecedent stimulus or agent
   "a bad reaction to the medicine";
   - response
    
2. (chemistry) a process in which one or more substances are changed into others
   "there was a chemical reaction of the lime with the ground water";
   - chemical reaction
    
3. An idea evoked by some experience
   "his reaction to the news was to start planning what to do"
    
4. A response that reveals a person's feelings or attitude
   "he was pleased by the audience's reaction to his performance"; "John feared his mother's reaction when she saw the broken lamp"
    
5. An action taken in response or opposition to something
   "his style of painting was a reaction against cubism"
    
6. Extreme conservatism in political or social matters
   "the forces of reaction carried the election"
    
7. (mechanics) the equal and opposite force that is produced when any force is applied to a body
   "every action has an equal and opposite reaction"

Derived forms: reactions

Type of: activity, bodily function, bodily process, body process, chemical action, chemical change, chemical process, conservatism, conservativism, force, idea, opposition, reception, resistance, response, thought

Encyclopedia: Reaction