reaction (reactions plural )
1 n-var Your reaction to something that has happened or something that you have experienced is what you feel, say, or do because of it.
Reaction to the visit is mixed...
2 n-count A reaction against something is a way of behaving or doing something that is deliberately different from what has been done before.
All new fashion starts out as a reaction against existing convention...
3 n-sing If there is a reaction against something, it becomes unpopular.
Premature moves in this respect might well provoke a reaction against the reform...
4 n-plural Your reactions are your ability to move quickly in response to something, for example when you are in danger.
The sport requires very fast reactions.
5 n-uncount Reaction is the belief that the political or social system of your country should not change., (disapproval)
Thus, he aided reaction and thwarted progress.
6 n-count A chemical reaction is a process in which two substances combine together chemically to form another substance.
Ozone is produced by the reaction between oxygen and ultra-violet light...
7 n-count If you have a reaction to a substance such as a drug, or to something you have touched, you are affected unpleasantly or made ill by it.
Every year, 5000 people have life-threatening reactions to anaesthetics...