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, assuming no change in the laws governing succession. 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;...