billionaire

American  

[bil-yuh-nair, bil-yuh-nair] / ˌbɪl jəˈnɛər, ˈbɪl jəˌnɛər /

noun

billionaires plural

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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Other Word Forms

Noun Inflected Forms

• billionaires
  plural

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

If even a high-profile billionaire global philanthropist is in the dark, what does that mean for the billions of women with less than a fraction of her resources?

From Salon • Jun. 14, 2026

Take, for example, a certain billionaire who seemingly would prefer to be a trillionaire: Elon Musk.

From Los Angeles Times • Jun. 14, 2026

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

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

From "Millionaires for the Month" by Stacey McAnulty