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

Billionaire Michael Bloomberg spent more than $260 million to win three terms as New York City mayor.

From Los Angeles Times • May 6, 2026

The 2026 Billionaire Tax Act is novel in the U.S.

From The Wall Street Journal • May 2, 2026

Billionaire Bill Ackman’s star power, strong long-term investment record, and an unusual incentive may not create big demand for his new closed-end equity fund, Pershing Square USA, which is expected to price later today.

From Barron's • Apr. 28, 2026

Billionaire investor Bill Ackman is taking his hedge fund Pershing Square Inc. public on Wednesday — and at the same time launching an initial public offering for a new closed-end fund.

From MarketWatch • Apr. 28, 2026

“I’d make a go at Little Orphan Billionaire myself, except he wouldn’t stop looking at you. Hey, speaking of which, here’s a fascinating piece of trivia: Guess who gets Pickett’s billions if he dies?”

From "Turtles All the Way Down" by John Green