Definify.com
Webster 1913 Edition
Reaction
Re-ac′tion
(rē̍-ăk′shŭn)
, Noun.
[Cf. F.
réaction
.] 1.
Any action in resisting other action or force; counter tendency; movement in a contrary direction; reverse action.
2.
(Chem.)
The mutual or reciprocal action of chemical agents upon each other, or the action upon such chemical agents of some form of energy, as heat, light, or electricity, resulting in a chemical change in one or more of these agents, with the production of new compounds or the manifestation of distinctive characters. See
Blowpipe reaction
, Flame reaction
, under Blowpipe
, and Flame
. 3.
(Med.)
An action induced by vital resistance to some other action; depression or exhaustion of vital force consequent on overexertion or overstimulation; heightened activity and overaction succeeding depression or shock.
4.
(Mech.)
The force which a body subjected to the action of a force from another body exerts upon the latter body in the opposite direction.
Reaction
is always equal and opposite to action, that is to say, the actions of two bodies upon each other are always equal and in opposite directions. Sir I. Newton (3d Law of Motion).
5.
(Politics)
Backward tendency or movement after revolution, reform, or great progress in any direction.
The new king had, at the very moment at which his fame and fortune reached the highest point, predicted the coming
reaction
. Macaulay.
Reaction time
(Physiol.)
, in nerve physiology, the interval between the application of a stimulus to an end organ of sense and the reaction or resulting movement; – called also
– physiological time
. Reaction wheel
(Mech.)
, a water wheel driven by the reaction of water, usually one in which the water, entering it centrally, escapes at its periphery in a direction opposed to that of its motion by orifices at right angles, or inclined, to its radii.
Webster 1828 Edition
Reaction
REAC'TION
,Noun.
1.
In physics, counteraction; the resistance made by a body to the action or impulse of another body, which endeavors to change its state, either of motion or rest. Action and reaction are equal.2.
Any action in resisting other action or power.Definition 2024
reaction
reaction
English
Noun
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.
Synonyms
Derived terms
Related terms
Translations
action in response to an event
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chemical transformation
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