A flash is a sudden burst of light or of something shiny or bright.

If a light flashes or if you flash a light, it shines with a sudden bright light, especially as quick, regular flashes of light.

You talk about a flash of something when you are saying that it happens very suddenly and unexpectedly.

If something flashes past or by, it moves past you so fast that you cannot see it properly.

If something flashes through or into your mind, you suddenly think about it.

If you flash something such as an identity card, you show it to people quickly and then put it away again.

If a picture or message flashes up on a screen, or if you flash it onto a screen, it is displayed there briefly or suddenly, and often repeatedly.

If you flash news or information to a place, you send it there quickly by computer, satellite, or other system.

If you flash a look or a smile at someone, you suddenly look at them or smile at them.

If someone's eyes flash, they suddenly show a strong emotion, especially anger.

Flash is the use of special bulbs to give more light when taking a photograph.

A flash is the same as a flashlight .

If you describe something as flash, you mean that it looks expensive, fashionable, and new.

If you describe an achievement or success as a flash in the pan, you mean that it is unlikely to be repeated and is not an indication of future achievements or success.

If you say that something happens in a flash, you mean that it happens suddenly and lasts only a very short time.

If you say that someone reacts to something quick as a flash, you mean that they react to it extremely quickly.

If your mind flashes back to something in the past, you remember it or think of it briefly or suddenly.