Skip to definition.
Get the FREE one-click dictionary software for Windows or the iPhone/iPad and Android apps


Noun: light speed
  1. The speed at which light travels in a vacuum; the constancy and universality of the speed of light is recognized by defining it to be exactly 299,792,458 meters per second
    - speed of light, c

Derived forms: light speeds

Type of: constant, speed, velocity

Encyclopedia: Light speed