# flash

/ˈfɫæʃ/ (US) · /flˈæʃ/ (UK)

Source: https://englishreference.com/word/flash
Updated: 2026-06-19

## Senses

### 1. burst of light

noun · CEFR A2

a sudden, brief, and bright light.

For teachers: a sudden and brief emission of light, often intense in nature.

- A flash of lightning lit up the dark sky for a second.
- The sudden flash of the explosion was visible from several miles away, momentarily blinding the observers.

### 2. photography

noun · CEFR B1

a small light on a camera that makes a bright burst to help take photos in the dark.

For teachers: an electronic device or bulb used in photography to produce a brief, intense light for illumination.

- Don't use the flash in the museum because it might damage the old paintings.
- The photographer adjusted the external flash to bounce the light off the ceiling, creating a softer effect for the portrait.

### 3. a short moment

noun · CEFR B1

a very short period of time.

For teachers: an extremely brief interval of time; often used in the phrase 'in a flash'.

- The summer holidays seemed to go by in a flash.
- The entire sequence of events occurred in a flash, leaving the witnesses struggling to recall the exact order of the accident.

### 4. sudden idea or feeling

noun · CEFR B2

a sudden and powerful thought or emotion.

For teachers: a sudden and brilliant burst of an abstract quality, such as wit, genius, or insight.

- I had a flash of inspiration and finally solved the puzzle.
- In a rare flash of genius, the engineer proposed a solution that bypassed the structural limitations of the original design.

### 5. to shine briefly

verb · CEFR B1

to shine with a bright light for a very short time.

For teachers: to emit a brief or intermittent light; can be transitive or intransitive.

- The lighthouse flashed its warning across the stormy sea.
- The diamond flashed brilliantly as she moved her hand under the gallery spotlights.

### 6. to move quickly

verb · CEFR B2

to move very fast past someone or something.

For teachers: to move at great speed in a specified direction.

- A red sports car flashed past us on the motorway.
- The high-speed train flashed through the station without stopping, creating a powerful gust of wind on the platform.

### 7. to show quickly

verb · CEFR B2

to show something to someone very quickly.

For teachers: to make something visible for a very brief duration, often to prove identity or status.

- The officer flashed his badge and asked to enter the building.
- He flashed a quick smile of encouragement before stepping onto the stage to begin his presentation.

### 8. computing

verb · CEFR C1 · Technical

to update the software on a piece of hardware, like a phone or computer part.

For teachers: to overwrite or update the firmware in a non-volatile memory chip.

- You need to flash the latest BIOS to support the new processor.
- The technician warned that if the power failed while flashing the firmware, the device could become permanently unusable.

### 9. showy or expensive

adjective · CEFR B2 · British English · Informal

looking expensive and impressive, often in a way that tries to get attention.

For teachers: ostentatiously expensive or stylish; intended to impress others.

- He drives a flash car but he doesn't have much money in the bank.
- The new nightclub was a bit too flash for my taste, with gold-plated fixtures and overpriced cocktails.

## Examples

- A flash of lightning lights up the sky.
- The photographer used a flash to take a clear picture in the dark room.
- He had a sudden flash of insight, realizing the solution to the problem that had troubled him for weeks.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.