replace, substitute, inherit

代 is composed of the radical 人 (person) and 弋 (shoot). 弋 is a pictograph of a wooden stake. A wooden stake can be used as a marker to identify boundaries. Therefore, 代 conveys the idea of a person taking the place of a wooden stake to guard the border, and thus carries the meaning of substitution or replacement. In addition, a person is a living being and after standing guard for a period of time must find another person to take over the work. From this, 代 also means to succeed or to inherit.