1. (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.

2. (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.

3. (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.

acknowledge act answer answer back be affected be in tune be inspired be involved be moved behave care about catch the flame catch the infection change color color with emotion come back come back at dig echo empathize with flash back function give acknowledgment give answer identify with operate perform proceed reciprocate recur reecho rejoin relate to emotionally renovate reply respond retaliate retort return return answer return for answer reverberate revert riposte say say in reply share shoot back snap back sympathize with take take the bait talk back turn turn back work