verb
- Show a response or a reaction to something.
- Act against or in opposition to.
- usage: "She reacts negatively to everything I say"
- Undergo a chemical reaction; react with another substance under certain conditions.
- usage: "The hydrogen and the oxygen react"
WordNet 3.0 © 2006 by Princeton University
- (v.t.) To act or perform a second time; to do over again; as, to react a play; the same scenes were reacted at Rome.
- (v.i.) To act upon each other; to exercise a reciprocal or a reverse effect, as two or more chemical agents; to act in opposition.
- (v.i.) To return an impulse or impression; to resist the action of another body by an opposite force; as, every body reacts on the body that impels it from its natural state.
Webster's Revised Unabridged Dictionary
Department of Defense Dictionary of Military and Associated Terms. 31 January 2011.