reaction

noun

1.
(chemistry) a process in which one or more substances are changed into others
Derived from:
react
2.
an idea evoked by some experience
3.
a bodily process occurring due to the effect of some antecedent stimulus or agent
Derived from:
react
4.
(mechanics) the equal and opposite force that is produced when any force is applied to a body
5.
a response that reveals a person's feelings or attitude
Derived from:
react
6.
extreme conservatism in political or social matters
Derived from:
reactionary
7.
doing something in opposition to another way of doing it that you don't like