Light-year

1 definition found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Light-year \Light-year\, Light year \Light year\ (Astron.)
     1. The distance over which light can travel in a year's time
        in a vacuum, 5.88 trillion miles (9.46 trillion
        kilometers); -- used as a unit in expressing stellar
        distances. It is more than 63,000 times as great as the
        distance from the earth to the sun. The star nearest to


        the earth's sun is about 4 light years distant.
        [Webster 1913 Suppl. +PJC]
  
     2. a very large difference; -- used figuratively to express
        great differences (of distance, quality, time) in
        comparisons. "Although having the same rank and salary,
        they were light-years apart in their ability to perform
        their jobs."
        [PJC]