/ riˈækʃn; NAmE / noun
TO EVENT / SITUATION
1.
[ C , U ] reaction (to sb/sth) what you do, say or think as a result of sth that has happened :
What was his reaction to the news?
My immediate reaction was one of shock.
A spokesman said the changes were not in reaction to the company's recent losses.
There has been a mixed reaction to her appointment as director.
The decision provoked an angry reaction from local residents.
I tried shaking him but there was no reaction.
CHANGE IN ATTITUDES
2.
[ C , usually sing. , U ] reaction (against sth) a change in people's attitudes or behaviour caused by disapproval of the attitudes, etc. of the past :
The return to traditional family values is a reaction against the permissiveness of recent decades.
TO DRUGS
3.
[ C , U ] a response by the body, usually a bad one, to a drug, chemical substance, etc. :
to have an allergic reaction to a drug
TO DANGER
4.
reactions [ pl. ] the ability to move quickly in response to sth, especially if in danger :
a skilled driver with quick reactions
AGAINST PROGRESS
5.
[ U ] opposition to social or political progress or change :
The forces of reaction made change difficult.
SCIENCE
6.
[ C , U ] ( chemistry ) a chemical change produced by two or more substances acting on each other :
a chemical / nuclear reaction
—see also chain reaction
7.
[ U , C ] ( physics ) a force shown by sth in response to another force, which is of equal strength and acts in the opposite direction
••
WORD ORIGIN
mid 17th cent.: from react + -ion , originally suggested by medieval Latin reactio(n-) , from react- done again, from the verb reagere .