nanosecond

noun

nano·​sec·​ond ˈna-nə-ˌse-kənd 

-kənt

1

: one billionth of a second

2

: 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.

Synonyms

• minute
• second
• heartbeat
• moment

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

While incredibly bright, the event only lasted less than 30 nanoseconds. —Eric Lagatta, USA Today, 28 June 2025

The burst was less than 30 nanoseconds long — a remarkably short duration for any radio burst. —Sam Walters, Discover Magazine, 26 June 2025

None of its systems would have been capable of producing this nanosecond signal. —Robert Lea, Space.com, 25 June 2025

Nuggets and Clippers players gazed up at the jumbotron together and tried to litigate the nanoseconds. —Bennett Durando, Denver Post, 27 Apr. 2025

Word History

Etymology

International Scientific Vocabulary

First Known Use

1958, in the meaning defined at sense 1

Rhymes for nanosecond

• femtosecond
• microsecond
• millisecond
• picosecond
• beckoned
• reckoned
• second
• seconde

Kids Definition

nanosecond

noun

nano·​sec·​ond ˈnan-ə-ˌsek-ənd 

-ənt

: one billionth of a second

Medical Definition

nanosecond

noun

nano·​sec·​ond -ˌsek-ənd, -ənt 

: one billionth of a second

—abbreviation ns, nsec