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.
Republican Assemblymember David Tangipa argues California has already spent billions of dollars addressing an issue that's simply getting worse. Darrielle Fair, CBS News, 20 Aug. 2026 Budget estimates project billions of dollars in deficits over the next few years. Torrey Snow, Baltimore Sun, 19 Aug. 2026 The states are seeking changes to user experiences for Facebook and Instagram as well as financial damages, which could include billions of dollars in penalties. ABC News, 19 Aug. 2026 Now the Department of Justice is knocking on the door, and Walter is scrambling to unwind deals and pay back billions before the feds bring the hammer down. Dieter Kurtenbach, Mercury News, 19 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 22 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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