some situation or event that is thought about; "he kept drifting off the topic"; "he had been thinking about the subject for several years"; "it is a matter for the police"
doing something in opposition to another way of doing it that you don't like; "his style of painting was a reaction against cubism"
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"
an idea evoked by some experience; "his reaction to the news was to start planning what to do"
extreme conservatism in political or social matters; "the forces of reaction carried the election"
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"
(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"
a certain degree of unwillingness; "a reluctance to commit himself"; "his hesitancy revealed his basic indisposition"; "after some hesitation he agreed"
(physics) opposition to magnetic flux (analogous to electric resistance)