Formal or literary term for a person who inherits a position, title, or legacy. Often used in historical, legal, or ceremonial contexts.
He was raised as the heir to the throne.
Choosing a successor for the company is a difficult issue.
The kanji 後 means 'after' or 'behind', and 嗣 means 'inherit' or 'succeed'. Together they form a compound meaning 'one who inherits after'. The exact historical derivation is uncertain, but the word is used in classical and formal contexts.