Meaning of REACTION in English

REACTION

[re.ac.tion] n (ca. 1611) 1 a: the act or process or an instance of reacting b: resistance or opposition to a force, influence, or movement; esp: tendency toward a former and usu. outmoded political or social order or policy

2: a response to some treatment, situation, or stimulus "her stunned ~ to the news"; also: such a response expressed verbally "critical ~ to the play"

3: bodily response to or activity aroused by a stimulus: a: an action induced by vital resistance to another action; esp: 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 English vocab.      Английский словарь Merriam Webster.