react

To act in response to or under the influence of a stimulus or prompting.

To act in opposition to a former condition or act.

To act reciprocally or in return.

To undergo a reaction.

To cause (a substance or substances) to undergo a reaction.

To act or perform anew; reenact: as, to react a play.

To exert, as a thing acted upon, an opposite action upon the agent.

To act, after being acted upon, in a manner directly opposed to the first action, and in increased measure.

To act mutually or reciprocally upon each other, as two or more chemical agents.

To act or perform a second time; to do over again; to reenact