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

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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 Eastern time on Thursday, to be proved right on Twitter and cable news approximately seven nanoseconds later. Drew Goins, Washington Post, 28 June 2024 No one believed for a greased nanosecond that anyone in this cast was a high schooler. Scott Hocker, theweek, 1 May 2024 An accounting revolution of that kind would be highly desirable, not only for society but also for shareholders, at least for those who care about more than what a firm’s share price will be for the next few nanoseconds. Diane Coyle, Foreign Affairs, 1 Sep. 2015 Don’t think for a nanosecond the prospects in this year’s NBA Draft class haven’t heard the noise from pundits, suggesting the collection of talent is among the worst in more than two decades. Roderick Boone, Charlotte Observer, 15 May 2024 See all Example Sentences for nanosecond 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'nanosecond.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

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 21 Jul. 2024.

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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