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.
Relations between Beijing and Cairo — the recipient of billions of dollars in military aid from Washington — have improved as China takes a more assertive role in the Middle East, analysts noted. semafor.com, 2 Sep. 2026 Some ministers also raised the idea of using billions of euros in frozen Russian assets to help meet more of Ukraine’s military and economic needs. Lorne Cook, Los Angeles Times, 2 Sep. 2026 Ballmer poured billions into the team, including paying for its new arena, which opened in Inglewood in 2024 and was used as the site of the NBA All-Star Game in February. Andrew Greif, NBC news, 2 Sep. 2026 Every few years, devastating fires in major cities left underwriters paying damages that would run into the billions today. Alison J. Stein, HubSpot, 1 Sep. 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 4 Sep. 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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