lightning: a sudden burst of brilliant light, seen rather than heard, that lights up everything at once.
This is the ordinary Greek word for lightning, the flash that splits open a storm sky. It names the sight and not the sound, which is why in Revelation it travels alongside a separate word for thunder (βροντή) rather than covering both. Where the general word for light (φῶς) can mean a steady glow that stays, this word is a burst that is over as soon as it comes.
When the Gospels reach for it, they are almost always drawing a picture, and the point of the picture is usually not speed:
- In Matthew 24:27 and Luke 17:24 it stands for an arrival that lights the sky from one horizon to the other, so that nobody needs to be told it happened.
- In Matthew 28:3 it stands for the blazing look of a messenger from heaven, a face too bright to hold in view.
- In Luke 10:18 it stands for a fall that is instant and final, straight down out of the sky.
One use has nothing to do with weather. In Luke 11:36 the word names the beam a household lamp throws across a room, the brightness that actually reaches you from the flame. What ties that to a storm is not the sky but the brilliance: the same word covers the blaze of a bolt and the bright shining of a small lamp.
In Revelation the flashes belong to a fixed set of signs that break out whenever God's presence stirs: lightning, rumblings, thunder, and an earthquake. The scene is built from the storm on Sinai, and it makes the same claim each time it appears. God has acted, and no one on earth will be able to say they missed it.