The word "偿还" is formed by combining two individual characters, each contributing a core semantic idea to create a compound meaning. The first character, "偿" (cháng), is itself composed of the radical "亻" (person) and the phonetic component "尝" (which carries the idea of tasting or experiencing, but here contributes the sense of fulfilling or satisfying an obligation). The second character, "还" (huán), depicts the idea of movement or return, historically shown by the radical "辶" (to walk) combined with "不" (which here, through evolution, contributes to the meaning of circling back). When placed together, "偿" provides the notion of fulfilling what is due, and "还" concretizes it as the act of returning something, thus visually and conceptually forming the complete idea of "to repay" or "to make restitution".