A more thorough explanation:

Definition: Heiress is a woman who inherits a large amount of money or property from a family member who has passed away.

Example: When her grandfather died, Jane became the heiress to his fortune.

Explanation: This example illustrates the definition of heiress because Jane inherited a large amount of money from her grandfather after he passed away. As the only living relative, she became the heiress to his estate.