[{"Bold_text": "noun", "List Items": ["reciprocal action, effect, or influence.", "Physics.the direct effect that one kind of particle has on another, in particular, in the emission or absorption of one particle by another.the mathematical expression that specifies the nature and strength of this effect.", "the direct effect that one kind of particle has on another, in particular, in the emission or absorption of one particle by another.", "the mathematical expression that specifies the nature and strength of this effect."]}]