A crown prince or hereditary prince is the heir apparent to the throne in a royal or imperial monarchy. The female form of the title is crown princess, which may refer either to an heiress apparent or, especially in earlier times, to the wife of the person styled crown prince.
Throngs before the Imperial Palace in Japan awaiting the appearance of Crown Prince Hirohito for the recent proclamation of his official recognition as the heir apparent to the Japanese Imperial Throne – New York Times, 1916.