# speed of light

> English word · Noun

## Definitions
1. The speed of electromagnetic radiation, which in a perfect vacuum is equivalent to 299,792,458 metres per second.
2. A very rapid speed.
3. A rate of travel of a signal equal to one cell per generation, the fastest possible speed in the Moore and von Neumann neighborhoods.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/speed-of-light