Definitions of reaction

  1. ( chemistry) a process in which one or more substances are changed into others; " there was a chemical reaction of the lime with the ground water"
  2. doing something in opposition to another way of doing it that you don't like; " his style of painting was a reaction against cubism"
  3. a bodily process occurring due to the effect of some foregoing stimulus or agent; " a bad reaction to the medicine"; " his responses have slowed with age"
  4. an idea evoked by some experience; " his reaction to the news was to start planning what to do"
  5. extreme conservatism in political or social matters; " the forces of reaction carried the election"
  6. a response that reveals a person's feelings or attitude; " he was pleased by the audience's reaction to his performance"; " John feared his mother's reaction when she saw the broken lamp"
  7. ( mechanics) the equal and opposite force that is produced when any force is applied to a body; " every action has an equal and opposite reaction"
  8. A regular or characteristic response to a stimulation of the nerves.
  9. A test for typhoid fever based on the fact that blood serum of one affected, in a bouillon culture of typhoid bacilli, causes the bacilli to agglutinate and lose their motility.
  10. Any action in resisting other action or force; counter tendency; movement in a contrary direction; reverse action.
  11. 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.
  12. 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.
  13. The force which a body subjected to the action of a force from another body exerts upon the latter body in the opposite direction.
  14. Backward tendency or movement after revolution, reform, or great progress in any direction.
  15. Return action or influence; response to influence or effort exerted; a return to a former or opposite state of things; contrary action following the effects of other action; the equal force that a body exerts on an opposing force; chemical change; a chemical process or its result.
  16. Action following and contrary to previous action; mutual action.
  17. Reactive, reactionary.
  18. Reverse or return action.
  19. The mutual action of chemical agents, or its result.
  20. Counteraction; reciprocal action; action in the contrary, specially backward, direction.
  21. The resistance made by a body to the action or impulse of another body; an action or force arising in opposition to another which has preceded.

Usage examples for reaction

  1. He saw, too, with profound sorrow, unmistakable signs everywhere of reaction in religion, politics, society. – Herbert Spencer by J. Arthur Thomson
  2. Then presently a reaction would set in, and he would be seized with remorse. – Mark Twain, A Biography, 1835-1910, Complete The Personal And Literary Life Of Samuel Langhorne Clemens by Albert Bigelow Paine Last Updated: February 20, 2009
  3. Alexander now hurled his greatest weapon, and stunned reaction in a moment. – The Great Events by Famous Historians, Vol. 17 by Charles Francis Horne
  4. No doubt it was a reaction from the excitement of the afternoon before. – The Manor House School by Angela Brazil
  5. For a fit of laughter which has been indulged to excess almost always produces a violent reaction. – Plato's Republic by Plato
  6. But this reaction is a general phenomenon of nature; there is no action without reaction. – The Mechanism of Life by Stéphane Leduc
  7. Paul Brennan's reaction was a disappointment to himself. – The Fourth R by George Oliver Smith
  8. After a few moments she began to feel doubtful, a little uneasy, partly from a reaction which was natural, partly because she was not at all sure what either Quarrier or Major Belwether would think of the terms she was already on with Siward. – The Fighting Chance by Robert W. Chambers
  9. He has just been trying to keep up ever since he came, and this afternoon he made unusual effort; reaction of course followed, and at last he was so weary and troubled that he could not hide his feelings from us. – Without a Home by E. P. Roe
  10. Now they came to see her, and another reaction had set in. – Lady Anna by Anthony Trollope
  11. She had had a moment of great weakness, and then there had come the reaction- carried almost too far by the force of the will. – The Translation of a Savage, Complete by Gilbert Parker Last Updated: March 12, 2009
  12. There's always the reaction to be gotten over with, if they're sudden. – The Bent Twig by Dorothy Canfield