Definition from Wiktionary, the free dictionary
Jump to: navigation, search


Alternative forms[edit]


  • (file)


lightspeed ‎(countable and uncountable, plural lightspeeds)

  1. The speed of light (in vacuum unless another medium is specified)
    • 1994, Ursula K. Le Guin, A Fisherman of the Inland Sea, Victor Gollancz (UK), ISBN 0575602392, published 1996, page 7:
      If we're going to a world a hundred light-years from here at near lightspeed, we spend according to our own perceptions, only a few minutes doing so and arrive only a few minutes older.
    • 2005, W. Strawn Douglas, Oracle And Other Stories, page 134:
      He paused, then finished, “with the drive from the Linz, he can do over 500 lightspeeds to meet us.