|coordinated universal time (kō-ôr'dn-ā'tĭd) Pronunciation Key
A highly accurate time scale based on time measured by an atomic clock. Because coordinated universal time is unaffected by the gradual slowing of Earth's rotation, leap seconds are added as needed to synchronize it with the sidereal (rotation-based) universal time. Coordinated universal time is used internationally for scientific and technical purposes. Compare universal time.