reacˈtion noun

1. Action resisting other action
2. Mutual action
3. An action or change in an opposite direction
4. Backward tendency from revolution, reform or progress
5. Response to stimulus
6. The chemical action of a reagent
7. A physical or mental effect caused by medicines, drugs, etc
8. A transformation within the nucleus of an atom
9. Acidity or alkalinity
10. Feeling or thought aroused by, or in response to, a statement, situation, person, etc

reacˈtional adjective

reacˈtionarism noun

reacˈtionarist noun

reacˈtionary adjective

Of or favouring reaction, esp against revolution, reform, etc

A person who tends to oppose political change or who attempts to revert to past political conditions

reacˈtionism noun

reacˈtionist noun and adjective

Reactionary

reacˈtive adjective

1. Of or relating to reaction
2. Readily acted upon or responsive to stimulus
3. Produced by emotional stress
4. Relating to or having a reactance (electronics)

reacˈtively adverb

reacˈtiveness or reactivˈity noun

reacˈtor noun

1. Someone or something that undergoes a reaction
2. A device which introduces reactance into an electric circuit
3. A container in which a chemical reaction takes place
4. A nuclear reactor (qv)

reaction formation noun (psychology)

A mechanism whereby a person adopts a mode of behaviour that is the opposite of his or her true disposition

reaction time noun

The interval between stimulus and reaction

reaction turbine noun

A turbine in which the fluid expands progressively in passing alternate rows of fixed and moving blades, the kinetic energy continuously developed being absorbed by the latter