millisecond

noun

mil·​li·​sec·​ond ˈmi-lə-ˌse-kənd How to pronounce millisecond (audio)
-kənt
: one thousandth of a second

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A millisecond isn't long enough for the blink of an eye, but a few milliseconds may determine the winner of a swim race or a hundred-yard dash. With the ever-increasing speed of modern technology, even a millisecond has started to seem a little sluggish; computer operations are now measured in nanoseconds—that is, billionths of a second.

Examples of millisecond in a Sentence

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.
In conversation, humans typically expect a reply within a few hundred milliseconds. — Ran Inbar, Forbes.com, 10 July 2026 The bursts last a few milliseconds to a few hundred seconds, and are thought to be caused by the merger of two neutron stars (the short bursts), or the collapse of large stars, creating a black hole (the long ones). — Jeffrey Kluger, Time, 2 July 2026 Called the Lorimer Burst, after the team leader who discovered it, the flash was far more luminous than anything ever seen like it, and, still more astonishing, the entire event lasted only about 5 milliseconds. — Phil Plait, Scientific American, 26 June 2026 Seltz’s system crawls hundreds of millions of pages a day, and returns results in under 200 milliseconds. — Jeremy Kahn, Fortune, 24 June 2026 See All Example Sentences for millisecond

Word History

Etymology

International Scientific Vocabulary

First Known Use

1909, in the meaning defined above

Time Traveler
The first known use of millisecond was in 1909

Rhymes for millisecond

See All Rhymes for millisecond

Browse Nearby Words

milliroentgen
millisecond
millisite
See all Nearby Words

Cite this Entry

“Millisecond.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/millisecond. Accessed 12 Jul. 2026.

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Kids Definition

millisecond

noun
mil·​li·​sec·​ond ˈmil-ə-ˌsek-ənd How to pronounce millisecond (audio)
also -ənt
: one thousandth of a second

Medical Definition

millisecond

noun
mil·​li·​sec·​ond ˈmil-ə-ˌsek-ənd, -ənt How to pronounce millisecond (audio)
: one thousandth of a second
—abbreviation ms, msec
Last Updated: - Updated example sentences
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