reciprocator

/rɪˈsɪprəkeɪtər/
noun
  1. A person or thing that reciprocates, especially someone who returns a favor, gesture, or feeling.
    • The machine acts as a reciprocator, moving the arm back and forth.
    • In negotiations, a good reciprocator builds trust.
    • He is a generous reciprocator, always returning kindness.
What does "reciprocator" mean? | whatsthatwordmean | whatsthatwordmean