To counter, retort or retaliate.
To move backwards and forwards, like a piston.
To exchange two things, with both parties giving one thing and taking another thing.
To give something else in response (where the "thing" may also be abstract, a feeling or action) To make a reciprocal gift.
To do something harmful or negative to get revenge for some harm; to fight back or respond in kind to an injury or affront.
To repay or requite by an act of the same kind.