1.NounThe speed of electromagnetic radiation, which in a perfect vacuum is equivalent to 299,792,458 metres per second.
"Early physicists developed insightful methods for measuring the speed of light."
2.NounA very rapid speed.
"When her cat figured out that a trip to the vet was in the offing, he took off towards the closet at the speed of light."
3.NounA rate of travel of a signal equal to one cell per generation, the fastest possible speed in the Moore and von Neumann neighborhoods.
"In a single generation, a cell can only influence its nearest neighbours, and so the speed of light (by analogy with the speed of light in physics) is the maximum rate at which information can propagate."