nano·​sec·​ond ˈna-nə-ˌse-kənd How to pronounce nanosecond (audio)
: one billionth of a second
: a very brief moment

Did you know?

The nonserious use of nanosecond is probably much more common than the proper technical use. In measurement terms such as nanosecond, nanogram, and nanometer, nano- means "billionth;" in other kinds of words, its meaning isn't quite so precise. In computers, the speed of reading and writing to random access memory (RAM) is measured in nanoseconds. By comparison, the speed of reading or writing to a hard drive or a CD-ROM player, or for information to travel over the Internet, is measured in milliseconds (thousandths of a second), which are a million times longer than nanoseconds.

Example Sentences

It happens in less than a nanosecond. a nanosecond was about all that it took her to accept his marriage proposal
Recent Examples on the Web As anyone who has been paying more than a nanosecond of attention to the Jan. 6 probe knows, blaming Pelosi for any of it stands in the school of goofy logic like blaming a homeowner for the burglary of her own home. Chicago Tribune, 23 Dec. 2022 Lang predicts that some of the particles produced in such a collision might come from this dark world, and a few in particular might decay more slowly, taking a whole nanosecond to disappear. Korey Haynes, Discover Magazine, 29 Apr. 2019 There is something in a nanosecond very lovely happening. Abbey White, The Hollywood Reporter, 6 Dec. 2022 Cadillac couldn’t figure out how to backlight them until someone suggested that medical lasers developed for eye surgery could use nanosecond pulses to cut the metal without distorting the metal from the heat of longer pulses for industrial lasers. Mark Phelan, Detroit Free Press, 18 Oct. 2022 Asked if this award could lead to their opening another Curate or expanding into a new destination, Button squashes that idea in a nanosecond. Gary Stern, Forbes, 12 July 2022 The gnocchi crackle against the teeth for a nanosecond before dissolving. Los Angeles Times, 30 June 2022 Much of the planet may be loosening coronavirus restrictions, but China, which can lock down a city in a nanosecond, is ever vigilant. Stephanie Yang, Los Angeles Times, 8 Feb. 2022 In its latest project, called Vault, prime archival pieces are dusted off for online sale — a venture that is mostly an exercise in frustration as Vault objects sell out in about a nanosecond. Robin Givhan, Washington Post, 15 Nov. 2021 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'nanosecond.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History


International Scientific Vocabulary

First Known Use

1958, in the meaning defined at sense 1

Time Traveler
The first known use of nanosecond was in 1958

Dictionary Entries Near nanosecond

Cite this Entry

“Nanosecond.” Dictionary, Merriam-Webster, Accessed 28 Jan. 2023.

Kids Definition


nano·​sec·​ond ˈnan-ə-ˌsek-ənd How to pronounce nanosecond (audio)
: one billionth of a second

Medical Definition


nano·​sec·​ond -ˌsek-ənd, -ənt How to pronounce nanosecond (audio)
: one billionth of a second
abbreviation ns, nsec
Last Updated: - Updated example sentences
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