Meaning of REACTION in English


— reactional , adj. — reactionally , adv.

/ree ak"sheuhn/ , n.

1. a reverse movement or tendency; an action in a reverse direction or manner.

2. movement in the direction of political conservatism or extreme rightism.

3. action in response to some influence, event, etc.: the nation's reaction to the President's speech.

4. Physiol. action in response to a stimulus, as of the system or of a nerve, muscle, etc.

5. Med.

a. the action caused by the resistance to another action.

b. a return to the opposite physical condition, as after shock, exhaustion, or chill.

6. Bacteriol. , Immunol. the specific cellular response to foreign matter, as in testing for allergies.

7. Chem. the reciprocal action of chemical agents upon each other; chemical change.

8. Also called nuclear reaction . Physics. a process in which a nucleus that is bombarded by a photon, particle, or other nucleus, emits a nucleon, alpha particle, or the like, without a significant change in its atomic weight.

9. Mech. the instantaneous response of a system to an applied force, manifested as the exertion of a force equal in magnitude but opposite in direction to the applied force.

10. Com. a decline in the market after an advance in prices.

[ 1635-45; RE- + ACTION, modeled on react ]

Random House Webster's Unabridged English dictionary.      Полный английский словарь Вебстер - Random House .