billionaire

American  

[bil-yuh-nair, bil-yuh-nair] / ˌbɪl yəˈnɛər, ˈbɪl yəˌnɛər /

noun

1. a person who has assets worth a billion or more dollars, euros, etc.

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billionaire British  

/ ˌbɪljəˈnɛə /

noun

1. a person whose assets are worth over a billion of the monetary units of his country

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Etymology

Origin of billionaire

First recorded in 1855–60, billion + -aire, on the model of millionaire

Explanation

Someone who lives in the U.S. and has money, property, and investments worth at least a billion dollars is a billionaire. Being a billionaire is dependent on a country's currency; in Europe, a net worth of a billion Euros makes someone a billionaire. There are around 2,500 Americans in this category, each possessing at least $1 billion — or a thousand million dollars. During the pandemic, U.S. billionaires increased their wealth by than $1.7 trillion dollars. The French billion was originally defined as "a million million," from bi-, "two," and million, but that was altered to "a thousand million."

Example Sentences

"I did not know that number," the billionaire Trump told the New York Post, adding "I would certainly like to be there, but I wouldn't pay it either, to be honest with you."

From Barron's • May 7, 2026

General Rob Bonta to scrutinize potential antitrust harms that would come from billionaire David Ellison’s proposed takeover of Warner Bros.

From Los Angeles Times • May 7, 2026

Last month, Texas billionaire John Arnold, who co-chairs the philanthropic organization Arnold Ventures, floated the compute-tax idea on X.

From The Wall Street Journal • May 7, 2026

A billionaire buying a fashion magazine is akin to a plane hurtling toward the ground, only for a passenger to confidently take the controls, despite having zero flying experience.

From Salon • May 6, 2026

The billionaire investor/philanthropist immediately phoned Alex Goldfarb, the Russian microbiologist and head of the Soros Foundation’s TB program in Russia.

From "Mountains Beyond Mountains" by Tracy Kidder and Michael French