regent
/ˈri:dʒənt; `ridʒənt/ (often 常作 Regent) n person appointed to rule a country while the monarch is too young, old, ill, etc, or is absent 摄政者. regent (often 常作 Regent), adj (following ns 用於名词之後) performing the duties of a Regent 摄政的
the Prince Regent 摄政王.