leap second

leap second

n.

A second of time, as measured by an atomic clock, added to or omitted from official timekeeping systems annually to compensate for changes in the rotation of the earth.

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leap second

n

(Mathematics & Measurements / Units) a second added to or removed from a scale for reckoning time on one particular occasion, to synchronize it with another scale

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leap second  (lp)

A second of time, as measured by an atomic clock, added to or omitted from official timekeeping systems annually to compensate for changes in the rotation of the Earth. See more at coordinated universal time.

Thesaurus

Noun

1.

leap second - a second (as measured by an atomic clock) added to or subtracted from Greenwich Mean Time in order to compensate for slowing in the Earth's rotation s, sec, second - 1/60 of a minute; the basic unit of time adopted under the Systeme International d'Unites