reciprocate

verb

1. 1

   To exchange two things, with both parties giving one thing and taking another thing.

2. 2

   To give something else in response (where the "thing" may also be abstract, a feeling or action) To make a reciprocal gift.

   “I gave them apples from my tree; they reciprocated with a pie and some apple jelly.”

3. 3

   To move backwards and forwards, like a piston.

   “A reciprocating engine.”

4. 4

   To counter, retort or retaliate.