from The American Heritage® Dictionary of the English Language, 4th Edition
- 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.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A second of time added to the year occasionally to compensate for variation in the rate of Earth's rotation relative to the absolute standards of time.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. 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
Sorry, no etymologies found.