- reäction (rare)
Old French reaction, from Latin reāctiō, from the verb reagō, from re- (“again”) + agō (“to act”); more at re-, action; equivalent to react + -ion.
reaction (plural reactions)
- An action or statement in response to a stimulus or other event.
- The announcement of the verdict brought a violent reaction.
- You were in the courtroom. What is your reaction?
- When I last tried to eat strawberries I had a terrible allergic reaction.
- (chemistry) A transformation in which one or more substances is converted into another by combination or decomposition.
- In this reaction, the acid and base will neutralize each other, producing a salt.
- (politics) Reactionary politics; a period in which reactionary thought or politics is resurgent or dominant.
- (Internet) An icon or emoji appended to a posted message by a user to express their feeling about it.
- Boudouard reaction
- Briggs-Rauscher reaction
- Finkelstein reaction
- reaction rate constant
action in response to an event
reaction (plural reactiones)