reciprocate
🇺🇸
/rɪˈsɪprəkeɪt/
🇬🇧
/rɪˈsɪprəkeɪt/
to give the same feelings, actions, or help in return
They wanted to reciprocate the kindness that had been shown to them.
to move back and forth in a straight line
The piston reciprocated inside the cylinder.