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

Every other leader expected on the shores of Lake Geneva has been the target of attacks, criticism or mockery from the Republican billionaire.

From Barron's • Jun. 13, 2026

It led to the birth of the modern stock market, which would go on to produce a historic run of personal wealth creation—becoming the very mechanism that would turn Rockefeller into the world’s first billionaire.

From The Wall Street Journal • Jun. 12, 2026

Approval had been expected because President Trump — who has friendly ties with Ellison and his father, tech billionaire Larry Ellison — favors the deal.

From Los Angeles Times • Jun. 12, 2026

The bout was hair vs. hair; whichever billionaire lost would be stripped of their mane in the ring.

From Slate • Jun. 11, 2026

Georgie scanned the room, probably searching for the tech billionaire, who was nowhere in sight.

From "Millionaires for the Month" by Stacey McAnulty