billion

American  

[bil-yuhn] / ˈbɪl jən /

noun

• billions,
  plural
• billion
  plural

1. a cardinal number represented in the U.S. by 1 followed by 9 zeros, and in Great Britain by 1 followed by 12 zeros.

2. a very large number.

   I've told you so billions of times.

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adjective

1. equal in number to a billion.

billion British  

/ ˈbɪljən /

noun

1. one thousand million: it is written as 1 000 000 000 or 10 ⁹

2. (formerly, in Britain) one million million: it is written as 1 000 000 000 000 or 10 ¹²

3. (often plural) any exceptionally large number

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determiner

1. (preceded by a or a cardinal number)

   1. amounting to a billion

      it seems like a billion years ago

   2. ( as pronoun )

      we have a billion here

Other Word Forms

Derived Forms

• billionth
  adjective

Inflected Forms

Nouns

• billion
  plural
• billions
  plural

Etymology

Origin of billion

1680–90; < French, equivalent to b ( i )- bi- ¹ + -illion, as in million

Compare meaning

How does billion compare to similar and commonly confused words? Explore the most common comparisons:

• billion vs. trillion

Explanation

A billion is 1,000,000,000. There are over 7 billion people in the world, the last time we checked. While billion may sounds like a made-up number like zillion — which just means a lot — it's a very real number, specifically 1,000,000,000. That's a pretty hard number to imagine, but one way to think of it is as a thousand millions. If you have a billion dollars, you're very rich: a billionaire. Money spent by the government is often measured in billions. In England, this word often refers to a different number: 1,000,000,000,000, or one million millions.

Example Sentences

See Examples For:

billion billions

Glaciers across the wider Hindu Kush-Himalayan region are a vital water source for 240 million people in the mountains and another 1.65 billion downstream across South and Southeast Asia.

From Barron's ● Sep. 3, 2026

Nvidia is reportedly nearing a deal to buy AI platform Hugging Face for about $14 billion.

From Barron's ● Sep. 2, 2026

The discount retailer said it now expects sales of $5.63 billion to $5.71 billion for the year, up from its forecast from June for $5.4 billion to $5.48 billion.

From The Wall Street Journal ● Sep. 2, 2026

One of the primary investors in Aspiration was Ballmer, the former longtime CEO of Microsoft whose estimated net worth is $139 billion.

From Los Angeles Times ● Sep. 2, 2026

In 2000 there had been $130 billion in subprime mortgage lending, and 55 billion dollars’ worth of those loans had been repackaged as mortgage bonds.

From "The Big Short" by Michael Lewis

A huge wave of freezing water and debris killed more than 1,000 people and left nearly 4,500 missing, with Kathmandu warning reconstruction costs could run into the "billions of dollars".

From Barron's ● Sep. 2, 2026

Building a new one would involve billions of dollars and take years to develop.

From The Wall Street Journal ● Sep. 2, 2026

Big tech companies are turning to the same bond markets to raise hundreds of billions of dollars for investments in AI data centres.

From BBC ● Sep. 2, 2026

Because billions of people drink coffee or tea every day, even small effects on bone health could have broad implications.

From Science Daily ● Sep. 2, 2026

In addition to the billions of dollars that GSS raked in selling land that didn’t actually exist, they made a killing selling virtual objects and vehicles.

From "Ready Player One: A Novel" by Ernest Cline