leap second meaning
UK /liːp ˈsɛkənd/ US /lip ˈsɛkənd/ 3 syllables
leap second (noun): 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.
Definition of leap second
How to pronounce leap second
leap second is pronounced /liːp ˈsɛkənd/ in British English and /lip ˈsɛkənd/ in American English. It has 3 syllables.
More about leap second on Wikipedia.