Meaning of REACTION in English

REACTION

n.

Pronunciation: r ē - ' ak-sh ə n

Function: noun

Date: circa 1611

1 a : the act or process or an instance of reacting b : resistance or opposition to a force, influence, or movement especially : tendency toward a former and usually outmoded political or social order or policy

2 : a response to some treatment, situation, or stimulus <her stunned reaction to the news> also : such a response expressed verbally <critical reaction to the play>

3 : bodily response to or activity aroused by a stimulus: a : an action induced by vital resistance to another action especially : the response of tissues to a foreign substance (as an antigen or infective agent) b : depression or exhaustion due to excessive exertion or stimulation c : heightened activity and overaction succeeding depression or shock d : a mental or emotional disorder forming an individual's response to his or her life situation

4 : the force that a body subjected to the action of a force from another body exerts in the opposite direction

5 a (1) : chemical transformation or change : the interaction of chemical entities (2) : the state resulting from such a reaction b : a process involving change in atomic nuclei

Merriam Webster Collegiate English Dictionary.      Merriam Webster - Энциклопедический словарь английского языка.