light speed

Noun

lightspeed (countable and uncountable, plural lightspeeds)

1. The speed of light (in vacuum unless another medium is specified).
   • 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.1994, Ursula K. Le Guin, A Fisherman of the Inland Sea, Victor Gollancz (UK), published 1996, →ISBN, page 7

   Synonyms:

   speed of light

2. (colloquial, figuratively) An extremely fast speed.
   • In recent years, other activist terms have followed light-speed trajectories. The term “Latinx” overtook academic institutions and briefly became fashionable in the media, still prevalent in some influential publications, like The New Yorker, even though only 3 percent of Hispanics (or Latinos, if...2022 October 23, Pamela Paul, “Let’s Say Gay”, in The New York Times

   Synonyms:

   speed of light