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

Those experimental masses are about 500 billion trillion times smaller than Earth.

From Science Daily ● Sep. 20, 2026

This month, the U.K. outlined a space strategy backed by $10.4 billion in funding through 2030.

From MarketWatch ● Sep. 20, 2026

As of June 30, the association insured 696,000 properties, with potential losses of $788 billion.

From Los Angeles Times ● Sep. 20, 2026

Prices doubled every day, goods vanished from shelves, and, at its worst, the monthly inflation rate reached 79 billion percent.

From Slate ● Sep. 20, 2026

It sold no more credit default swaps to Wall Street but did nothing to offset the 50 billion dollars’ worth that it had already sold.

From "The Big Short" by Michael Lewis

Investment scams cost Americans billions of dollars every year — how to protect yourself.

From The Wall Street Journal ● Sep. 18, 2026

While everyone argues about whether AI will eventually bring about the apocalypse, hundreds of billions of dollars are being spent building the infrastructure underneath it.

From MarketWatch ● Sep. 18, 2026

"Fifa currently holds billions of dollars in accumulated reserves," it read.

From BBC ● Sep. 18, 2026

Because the system is so young, studying it gives astronomers a glimpse of what our own solar system may have looked like billions of years ago.

From Science Daily ● Sep. 17, 2026

A galaxy is composed of gas and dust and stars—billions upon billions of stars.

From "Cosmos" by Carl Sagan