IPA: /ˈhɛrɪtə/
KK: /ˈhɛrɪtər/
A person who receives property, money, or a title from someone who has died or passed it on.
As the only child, she was the sole heritor of her parents' estate.
Heritor is formed from "herit" (from Old French *heriter*, meaning to inherit) and "-or" (meaning one who). The word "heritor" refers to one who inherits or is entitled to inherit property or a title.
Think of someone who 'inherits' ('herit') something, and the '-or' indicates a person. An heritor is someone who is entitled to receive an inheritance.