/ɹiːˈækt/
noun
An emoji used to express a reaction to a post on social media.verb
To act or perform a second time; to do over again; to reenact.To return an impulse or impression; to resist the action of another body by an opposite forceTo act upon each other; to exercise a reciprocal or a reverse effect, as two or more chemical agents; to act in opposition.To cause chemical agents to react; to cause one chemical agent to react with another.