The word 报答 is formed through the conceptual fusion of two complementary ideas: 报 (bào), which carries the fundamental meaning of responding to or repaying an action, often with a sense of duty or consequence, and 答 (dá), which specifically denotes giving a reply or a direct response. When combined, they create a unified, reinforced concept where the sense of "reply" from 答 is elevated and given moral weight by the notion of "required return" from 报, thus forming the complete idea of conscientiously returning a favor or repaying kindness, embodying a cycle of action and grateful reciprocation.