noun
heir to a throne
Formal term for a person in line to succeed a monarch. Used in historical, political, or fantasy contexts.
王位継承者が決まっていないと、国が不安定になる。
If the heir to the throne is not decided, the country becomes unstable.
彼は王位継承者として育てられた。
He was raised as the heir to the throne.
Compound of 王位 (throne) + 継承 (succession) + 者 (person). The exact historical derivation is uncertain, but the components are standard Sino-Japanese morphemes.