1
US : a number equal to 1,000 million see Table of Numbers
also, British : a number equal to 1,000 milliard see Table of Numbers
2
: a very large number
billion adjective

Did you know?

How much is a billion? It might depend on whom you ask. Billion was borrowed from French in the late 1600s to indicate the number one million raised to the power of two, or a million million—a number represented by a 1 followed by 12 zeros. However, the French later changed their naming conventions so that a billion became a thousand million (a 1 followed by 9 zeros) and a trillion became a thousand thousand million (or a million million, the old billion). The French have since returned to the older system, but it was this new system that was adopted by American English speakers in the 1800s. In Britain, the newer system has seen increasing use since the 1950s, but the older sense is still sometimes used there as well.

Examples of billion in a Sentence

We could see a billion stars in the sky.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The company has had a decades-long presence in the country and invested billions in AI infrastructure and related skills training in Brazil, the leading economy in Latin America. Charlotte Hu, Time, 26 Aug. 2026 His government has implemented policies that slow energy permitting and development, canceled billions in grants for hundreds of clean energy projects and spent nearly $4 billion to buy back leases to stop offshore wind projects. ABC News, 26 Aug. 2026 Last month's numbers were fueled by billions in immigration enforcement funding from Congress and a hiring spree of thousands of ICE officers. Vanessa Romo, NPR, 26 Aug. 2026 The settlement is a fraction of the hundreds of billions of dollars Meta makes every year. Sonja Sharp, Los Angeles Times, 26 Aug. 2026 See All Example Sentences for billion

Word History

Etymology

French, from bi- + -illion (as in million)

First Known Use

1801, in the meaning defined at sense 2

Time Traveler
The first known use of billion was in 1801

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Cite this Entry

“Billion.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/billion. Accessed 29 Aug. 2026.

Kids Definition

1
: a number equal to 1,000 million : 1,000,000,000 see number
2
: a very large number
billion adjective
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