Skip to main content
Glite Dictionary
leap second

leap second

1 6.8
An extra second added to clocks so they match how fast the Earth turns
  • noun
  • /liːp ˈsɛkənd/
  • Specialized
translation icon : segundo intercalar
  • The next leap second will occur on December 31.
  • add a leap second

Examples

  • Technical systems sometimes experience glitches when a leap second is added to the world clock.

  • The atomic time clock is adjusted by leap seconds to maintain synchronicity with GMT.

  • A leap second was inserted at midnight last June, briefly making the day longer.

  • The international time standard occasionally includes a leap second to keep clocks in sync with Earth's rotation.

  • Many people are unaware of the leap second adjustment.

  • Standard time is adjusted by adding or subtracting a leap second from time to time.

  • The first leap seconds were added in June and December 1972.

Surface Forms

leap second singular
leap seconds plural

Morphology

leap + second

The meaning is directly compositional: 'leap' (a sudden/additional change) combined with 'second' (unit of time) yields the sense of an extra or adjusted second in timekeeping. Although technical, this follows the same transparent logic as 'leap year', so a B1 learner who knows the constituents can reasonably infer the concept.

Etymology

The term leap second comes from the image of a tiny leap, or jump, of one second on the clock when an extra second is added to the official world time. This extra second is put in when the Earth's spin slows or changes a little, so clocks stay accurate and the phrase means 'an extra second added to keep clocks correct'.