nano·​sec·​ond | \ ˈna-nə-ˌse-kənd How to pronounce nanosecond (audio) , -kənt\

Definition of nanosecond

1 : one billionth of a second
2 : a very brief moment

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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.

Examples of nanosecond in a Sentence

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

Instead, much shorter pulses of plasma—several nanoseconds—are used to ignite the fuel-air mix inside the cylinder. Jonathan M. Gitlin, Ars Technica, "Swapping spark plugs for nanopulses could boost engine efficiency by 20%," 26 June 2019 One can, however, add the second beam splitter at the very last nanosecond. Quanta Magazine, "Closed Loophole Confirms the Unreality of the Quantum World," 25 July 2018 The gadget, about the size of a toaster, uses charged mercury ions to keep its quartz oscillator true, and loses only about one nanosecond over four days. Jason Daley, Smithsonian, "How a Toaster-Sized Atomic Clock Could Pave the Way for Deep Space Exploration," 26 June 2019 So long ago—a historical nanosecond after Watergate and the fall of Saigon. David Remnick, The New Yorker, "The Chaotic Magic of Bob Dylan’s Rolling Thunder Revue," 10 June 2019 This material can be written in nanoseconds and hold on to that memory without power. John Timmer, Ars Technica, "Researchers make RAM from a phase change we don’t entirely understand," 18 Dec. 2018 Yet again, a few nanoseconds of speculation can occur between making an invalid access (accessing memory with a mismatched protection key) and the processor reporting the error, enabling information that should be protected to leak. Peter Bright, Ars Technica, "Spectre, Meltdown researchers unveil 7 more speculative execution attacks," 14 Nov. 2018 Computing takes nanoseconds; biology takes days, weeks, even years. Andy Kessler, WSJ, "The Chip That Changed the World," 26 Aug. 2018 Hands were suspended in the air after each piece, dropping for the next work after a nanosecond, preventing applause and creating two seamless program halves. Peter Dobrin,, "Pianist András Schiff is a master of detail at the Kimmel," 1 Apr. 2018

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.

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First Known Use of nanosecond

1958, in the meaning defined at sense 1

History and Etymology for nanosecond

International Scientific Vocabulary

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Statistics for nanosecond

Last Updated

5 Sep 2019

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Time Traveler for nanosecond

The first known use of nanosecond was in 1958

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English Language Learners Definition of nanosecond

technical : one billionth of a second
: a very short time


nano·​sec·​ond | \ -ˌsek-ənd, -ənt How to pronounce nanosecond (audio) \

Medical Definition of nanosecond

: one billionth of a second abbreviation ns, nsec

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to be made up of

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