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

Oracle co-founder, billionaire and conservative donor Larry Ellison is an old friend of the president’s.

From Los Angeles Times • Apr. 30, 2026

The privately owned Dangote refinery, built by Nigeria's richest man, billionaire Aliko Dangote, came online in 2024.

From Barron's • Apr. 30, 2026

Such an arrangement could appeal to the president’s brand as the ultimate deal maker and billionaire businessman.

From Salon • Apr. 30, 2026

The billionaire appears to have purchased the 7,500-square-foot duplex, inside a storied New York building, in an off-market deal.

From The Wall Street Journal • Apr. 29, 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