leap second
noun
: an intercalary second added to Coordinated Universal Time to compensate for the slowing of the earth's rotation and keep Coordinated Universal Time in synchrony with solar time
Examples of leap second in a Sentence
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Some scientists predict that if Earth's rotation continues to speed up by just a few more milliseconds each year, a negative leap second might be needed around 2029, according to BBC Sky at Night Magazine, though the exact timing depends on future measurements.
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Daisy Dobrijevic, Space.com, 10 July 2025
To date, all adjustments to time have involved adding a leap second.
—Alice Gibbs, MSNBC Newsweek, 10 July 2025
The last leap second was positive and used at the end of December 2016.
—Jamie Carter, Forbes.com, 20 June 2025
Moreover, removing the leap second would actually make computerized timekeeping much harder, not easier, so there is simply no reason to do it.
—Aaron Shattuck, Scientific American, 18 Feb. 2025
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Daisy Dobrijevic, Space.com, 10 July 2025
To date, all adjustments to time have involved adding a leap second.
—Alice Gibbs, MSNBC Newsweek, 10 July 2025
The last leap second was positive and used at the end of December 2016.
—Jamie Carter, Forbes.com, 20 June 2025
Moreover, removing the leap second would actually make computerized timekeeping much harder, not easier, so there is simply no reason to do it.
—Aaron Shattuck, Scientific American, 18 Feb. 2025
See All Example Sentences for leap second
Cite this Entry
“Leap second.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/leap%20second. Accessed 21 Jul. 2025.
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