Heir apparent

An heir (female: heiress) is a person who has inherited something after the original owner's death. It is often a child after a parent dies.Richard Burn; John Burn, A New Law Dictionary (London: printed by A. Strahan and W. Woodfall, for T. Cadell, 1792), p. 423

Heir apparent and heir presumptive usually refer to someone who will inherit a royal or noble title:

An heir apparent is someone who will inherit at the death of the present title-holder.The Manual of Rank and Nobility, or Key to the Peerage  (London: Saunders and Otley, 1828), p. 43
A Crown Prince is an heir apparent to the throne in a monarchy.Jeremy Paxman, On Royalty: A Very Polite Inquiry Into Some Strangely Related Families (New York : PublicAffairs, 2008), p. 103

An heir presumptive is someone who may inherit unless someone with a better claim under the rules of succession is found.John Almon; John Debrett; et al., The Parliamentary register: or, History of the proceedings and debates of the House of Lords ... during the 14th-[18th] Parliament[s] of Great Britain [1774-1803] (London: Printed for J. Almon, 1775-1804), p. 75

King Charles III's oldest son is Prince William, who is thus the heir apparent of the British monarchy.

Prince Bertil of Sweden was the heir presumptive to his nephew King Carl XVI Gustav. The King's son, Prince Carl Philip became heir apparent when he was born, but when in 1980 the law of succession changed, his sister Princess Victoria became the world's first heiress apparent.

Monarchies that have used the title

Prussia
Japan
Sweden
Denmark
Greece

References

Category:Royalty and nobility
Category:Monarchy