heir apparent

An heir apparent is the first person in the order of succession and who cannot be displaced from inheriting by the birth of another person. A person who is currently first in the order of succession but could be displaced by the birth of a more eligible heir is an heir presumptive. Today these terms most commonly describe heirs to hereditary titles (e.g. titles of nobility) or offices, especially when only inheritable by a single person. Most monarchies designate the heir apparent as crown prince or crown princess, though many also grant them a specific substantive title: Prince of Orange in the Netherlands, Duke of Brabant in Belgium, Prince of Asturias in Spain (also granted to heirs presumptive), Prince of Wales in England and Wales; formerly Dauphin in the Kingdom of France, and Tsesa...