D defs.my
Entry 4 senses Webster, 1913

Interaction

/ĭnˌ-tẽr-ăk'-shən/ · In·ter·ac·tion · IPA /ˌɪn.tɚˈæk.ʃən/
01 n. Intermediate action.
  1. 1.
    Intermediate action.
  2. 2.
    Mutual or reciprocal action or influence; as, the interaction of the heart and lungs on each other.
  3. 3.
    The effect, such as exertion of a force, that one object exerts on another, especially the capture or emission of a particle.(Physics)
  4. 4.
    Communication between people, or the actions of people that affect others.