billionaire
n. countable B1 Intermediate US //ˌbɪɫjəˈnɛɹ// UK //bˌɪliənˈeə// bil·lion·aire
n. a person who has at least one billion dollars, pounds, or euros in money and property.
n. a person whose net worth is valued at one billion units or more of a major currency. Often used to describe the highest tier of global wealth and economic influence.
The young billionaire donated half of his wealth to charity.
The city's skyline is dominated by luxury towers owned by a reclusive billionaire.
Economists often debate whether the existence of a billionaire class is a sign of a healthy market or a symptom of systemic wealth inequality.
From billion + -aire.
Usage
Countable; often used as a modifier before another noun (e.g., 'billionaire investor').