reciprocate

verb

1. act, feel, or give mutually or in return

   verb.social

   Examples

   We always invite the neighbors and they never reciprocate!

   Source: WordNet 3.0

2. alternate the direction of motion of

   verb.motion

   Examples

   The engine reciprocates the propeller.

   Source: WordNet 3.0

3. To move forward and backward alternately; to recur in vicissitude; to act interchangeably; to alternate.

   verb

   Source: webster1913

4. To give and return mutually; to make return for; to give in return; to interchange; to alternate; as, to <i>reciprocate</i> favors.

   verb

   Source: webster1913